Semi-presidentialism, hybrid regimes, and political transitions under armed conflicts and exogenous shocks: A comparative statistical analysis

The global political landscape at the turn of the twenty-first century is increasingly shaped by protracted democratic transitions, autocratic regression, and the escalation of armed conflicts and other exogenous shocks (Diamond 2015; Diamond 2020; Gunitsky 2014; Hegre 2014; Houle, Kayser 2019; Levitsky, Ziblatt 2018; Lührmann, Lindberg 2019; Mansfield, Snyder 2002). These dynamics are particularly critical for nascent states with hybrid political regimes combining democratic and autocratic elements, where democratic institutions and procedures remain fragile, incomplete, or only partially institutionalized, and where informal power relations and enduring legacies of autocracy persist (Bermeo 2016; Hale 2015; Levitsky, Way 2010; Lührmann, Lindberg 2019), especially in times of war and in the post-war period. In such contexts, institutional design – particularly semi-presidentialism – plays a pivotal role in determining political stability, shaping regime trajectories toward democratization or autocratization, and influencing patterns of socio-economic development (Cheibub 2006; Cheibub et al. 2014; Elgie 2007; Elgie 2010; Elgie 2011; Elgie, McMenamin 2008; Sedelius, Linde 2017; Sedelius et al. 2024).

While previous research has extensively examined semi-presidentialism from institutional, political, and endogenous perspectives (Elgie 2007; Elgie 2010; Elgie 2011; Elgie, McMenamin 2008; Lytvyn 2023; Moestrup 2007; Protsyk 2005; Protsyk 2006; Schleiter, Morgan-Jones 2009; Sedelius 2006; Sedelius, Ekman 2010; Sedelius, Linde 2017; Sedelius, Mashtaler 2013; Skach 2007), its interaction with non-institutional, socio-economic, and exogenous factors – such as armed conflicts and wars (Sedelius et al. 2024; Yan 2023) – remains insufficiently explored. Most existing studies and empirical evidence focus on endogenous and institutional determinants, emphasizing how constitutional or political arrangements and executive–parliamentary relations affect political stability and regime performance (democratic or autocratic). Yet they often overlook the influence of extra-institutional and exogenous conditions that can stress, transform, or recalibrate political systems, including semi-presidential ones. This research gap is particularly salient from comparative and statistical perspectives, especially for nascent states characterized by hybrid regimes and incomplete political transitions, where exogenous shocks such as wars, armed conflicts, or crises may amplify existing vulnerabilities or trigger adaptive institutional and political responses.

The study addresses the gap by examining how different institutional and political types of semi-presidentialism – including premier-presidential, president-parliamentary, parliamentarized, presidentialized, and balanced forms – both shape and are shaped by political dynamics and regime transitions in nascent states with hybrid characteristics under the pressure of armed conflicts and other exogenous shocks. It asks: Under what conditions do semi-presidential institutional and political configurations foster or hinder democratization, autocratization, and socio-economic development in nascent states with hybrid regimes exposed to armed conflicts and other external shocks? By combining comparative, quantitative, and statistical methods, the study analyzes interactions between institutional and non-institutional (endogenous and exogenous) factors across 14 semi-presidential states meeting these criteria. It assesses variations in institutional design alongside the intensity and nature of armed conflict exposure, offering an analytical framework for identifying which semi-presidential models are most conducive to democratic resilience and effective governance in unstable environments.

The theoretical framework integrates institutionalist perspectives on executive–legislative relations under semi-presidentialism (Cheibub et al. 2014; Duverger 1980; Elgie 1999; Elgie 2004; Elgie 2005a; Elgie 2011; Lytvyn 2020; Lytvyn, Romanyuk 2021; Protsyk 2005; Protsyk 2006; Sartori 1995; Sedelius 2006; Sedelius, Ekman 2010; Shugart, Carey 1992; Skach 2007) with insights from the literature on hybrid regimes and political transformations driven by wars, crises, or other exogenous shocks (Bermeo 2016; Boin, ’t Hart 2012; Elgie 2007; Elgie 2010; Gunitsky 2014; Hale 2015; Hegre 2014; Houle, Kayser 2019; Levitsky, Way 2010; Sedelius, Linde 2017; Sedelius et al. 2024; Yan 2023). The analysis goes beyond endogenous institutional mechanisms – such as executive dualism, government responsibility, and inter-institutional conflict – to examine their interaction with non-institutional and exogenous factors, including wars, armed conflicts, and broader geopolitical shocks. This integrated approach allows for assessing how internal and external dynamics jointly shape regime trajectories and socio-economic outcomes across different variants of semi-presidentialism.

From an empirical standpoint, Ukraine exemplifies a contemporary case of a nascent state characterized by a hybrid regime, a protracted political transition, a semi-presidential institutional design, and an ongoing war. Comparable conditions – historical or current – can be observed in Cameroon, Georgia, Moldova, Sri Lanka, and Yemen, among others. This enables a comparative and statistical analysis, highlighting systematic patterns and distinctions in how semi-presidential systems respond to exogenous shocks (particularly armed conflicts), and clarifying which institutional configurations and hybrid political regimes are more conducive to democratic resilience (democratization) or, conversely, more prone to autocratic tendencies (autocratization).

Finally, the article is structured into four sections. The first section outlines the conceptual and theoretical framework, including typologies of institutional designs and prior findings on semi-presidentialism from the perspective of institutional or endogenous factors and democratic outcomes. The second section examines exogenous challenges – particularly armed conflicts, wars, and crises – as critical contexts shaping institutional dynamics under semi-presidentialism. The third section details the methodological design, including case selection criteria and institutional, political, and socio-economic indicators for analysis. The fourth section presents the results of the comparative and statistical analysis, providing insights into how different semi-presidential configurations influence democratization, autocratization, institutional resilience, inter-institutional conflict, and socio-economic development in nascent transitional states with hybrid regimes exposed to exogenous shocks.

Before proceeding to the comparative and statistical analysis, it is necessary to outline the theoretical and conceptual foundations for examining the prospects and risks – or outcomes – of semi-presidentialism under conditions of inter-institutional dynamics, political transition, and exogenous shocks such as war or armed conflict. This section defines and classifies systems of government, with particular attention to semi-presidentialism, and highlights their implications for processes of democratization and autocratization. The theorization integrates internal (endogenous) factors discussed here with external (exogenous) determinants that will be addressed in the following section.

Historically and in contemporary political science, scholars have employed either dichotomous (two-type) or trichotomous/quadripartite (three- or four-type) approaches to classify systems of government (Cheibub 2006; Cheibub 2014; Daly 2003; Duverger 1980; Eaton 2000; Elgie 1998; Elgie 2005b; Ganghof 2017; Krouwel 2003; Lijphart 1997; Linz 1990a; Linz 1990b; Sartori 1994a; Sedelius, Linde 2017; Shugart, Carey 1992). Until the 1980s and 1990s, the dominant tradition – still persisting in some analyses – was the dichotomous classification into parliamentarism and presidentialism. Comparative studies of the effects of systems of government on democratic or autocratic development were primarily conducted within these two categories. During this period, semi-presidentialism was either not yet conceptualized or considered a subtype of presidentialism or parliamentarism (Cheibub 2006; Cheibub et al. 2014; Eaton 2002; Kasapovic 1996; Krouwel 2003; Linz 1990a; Linz 1990b).

Since the 1980s and 1990s, particularly through the work of Duverger (1980; 1983; 1986; 1993), Sartori (1994a; 1994b; 1995), Elgie (1998; 1999; 2004; 2005; 2011), and later Sedelius (2006), a trichotomous classification – presidential, parliamentary, and semi-presidential systems – has become widely accepted. Some scholars (Ganghof 2017; Munkh-Erdene 2010) even propose a fourfold classification, distinguishing semi-parliamentarism and reflecting the empirical diversity of constitutional arrangements. Consequently, contemporary research increasingly analyzes systems of government in a more nuanced manner, considering their differential impacts on democratization and autocratization.

A widely cited method for identifying and classifying constitutional systems of government within the trichotomous framework is Elgie’s (1998) approach. His main indicators are the mode of presidential election (popular or non-popular) and the actor with authority over government’s collective responsibility and potential dismissal (president and/or parliament). Based on these indicators, political systems are classified as follows: (1) Parliamentarism: the president is elected non-popularly (mainly by parliament), and the government is collectively responsible and can be dismissed solely by the legislature. Monarchies also fall under this model if the government is responsible solely to parliament; (2) Presidentialism: the president is popularly elected for a fixed term, and the government (presidential administration) is not collectively responsible to parliament and cannot be dismissed by it; (3) Semi-presidentialism: the president is popularly elected for a fixed term, while the government, led by a prime minister, is collectively responsible and can be dismissed by parliament (and in some variants, also by the president). Elgie’s approach is constitutionally grounded, avoids relational bias, and provides clear criteria for identifying and comparing inter-institutional dynamics across states (Sedelius, Linde 2017).

Semi-presidentialism requires particular attention when studying political regime trajectories in transitional and fragile polities because it combines a popularly elected president with a prime-minister-headed government responsible to parliament and sometimes also to the president. This dual executive arrangement generates variable outcomes (risks and prospects), especially under democratic or autocratic transition, inter-institutional dynamics, war, and both internal (endogenous) and external (exogenous) factors. Semi-presidentialism, thus, is a heterogeneous system of government (Lytvyn 2020), with outcomes varying according to political and institutional, as well as domestic and international contexts. Elgie (2011), based on the nature of political leadership, identifies three types of semi-presidentialism: presidentialized, balanced, and parliamentarized systems.⁽¹⁾ Shugart and Carey (1992) distinguish president-parliamentary and premier-presidential systems, based on formal government and prime-ministerial responsibility.⁽²⁾ Skach (2007) and Lytvyn and Romanyuk (2021) further refine the classification of semi-presidentialism, considering party affiliation of presidents and prime ministers, party composition of governments and legislatures, and the dynamics of executive dualism, identifying fully or partially unified majority systems, divided majority systems (cohabitation), fully or partially unified minority systems, and divided minority systems.⁽³⁾

Semi-presidentialism’s variations and variability across different indicators raise questions about its suitability, particularly in unstable countries undergoing political transition shaped by internal and external factors. Such countries are often characterized by hybrid regimes, combining democratic and autocratic elements.⁽⁴⁾ This issue becomes particularly complex and contested when assessing the effectiveness of semi-presidentialism in nascent transitional states.⁽⁵⁾ Debate remains on whether divided government (cohabitation) under semi-presidentialism is stabilizing or destabilizing.

Duverger (1997) offered a largely positive assessment of semi-presidentialism, emphasizing that this institutional design can function effectively when the president stands in opposition to the parliamentary majority (and government) or to parliament as a whole. Similarly, Sartori (1994a: 121–140) argued that semi-presidential systems manage the challenges of divided government (cohabitation) more successfully than other constitutional models, since they tend to empower the political actor who enjoys stronger parliamentary backing. The system’s inherent political flexibility and institutional adaptability distinguish semi-presidentialism from presidentialism, which typically produces more rigid inter-institutional or intra-executive relations and entails higher risks of democratic transition, as well as from parliamentarism, which, though generally more democratic, is often prone to governmental and political instability. Building on this logic, subsequent scholarship has emphasized that semi-presidentialism’s flexible institutional and political arrangements allow for effective management of divided government or majority conflicts, thereby fostering political cooperation and coalition-building – conditions that may prove advantageous for democratic transition rather than autocratic regression, particularly in nascent states (Elgie 2010; Elgie, McMenamin 2011; Kim 2015; Lazardeux 2015; Sedelius, Ekman 2010; Sedelius, Linde 2017; Sedelius, Mashtaler 2013).

Conversely, Linz (1994) underscores the risks and adverse effects that semi-presidentialism (as well as presidentialism) may generate, particularly in nascent, transitional, conflict or post-conflict, and generally crisis-prone societies – drawing on the case of the Weimar Republic in Germany. He cautions that semi-presidentialism can be especially “threatening” to democracy because of the potential rivalry within the dual executive, notably when the president and the prime minister belong to opposing political parties and compete for political authority. Similarly, Stepan and Suleiman (2001) and Gherghina and Miscoiu (2013) highlight the danger of constitutional conflict between two executive figures, each endowed with democratic legitimacy – the president through popular election and the prime minister through the confidence of a popularly elected parliament. Elgie (2010), Elgie and McMenamin (2011), and Sedelius and Linde (2017), however, challenge this perspective, arguing that divided government or cohabitation in semi-presidential systems does not inherently precipitate democratic failure or autocratization in nascent states. Rather, presidents in such situations often retain sufficient institutional leverage and political capital to engage in negotiation, coalition-building, and conflict management, thereby mitigating the risks associated with executive dualism and divided government.

In this context, it is essential to recall that semi-presidentialism constitutes a heterogeneous institutional category, encompassing distinct and internally divergent types. Consequently, assessing its performance and democratic or autocratic potential as a single, unified model – particularly in transitional contexts – can be analytically misleading. Instead, the effects of different variants should be compared in relation to democratic development and the risks of autocratization. Empirically, Elgie and McMenamin (2008) demonstrated that divided government under semi-presidentialism is not inherently detrimental to democratic change, except perhaps in nascent states. However, presidentialized and balanced forms of semi-presidentialism are more frequently associated with poor democratic outcomes and undemocratic trajectories – especially in nascent states – whereas parliamentarized variants tend to correlate with higher levels of democratic performance, particularly across Central and Eastern Europe. Similar conclusions were reached by Elgie (2007), Moestrup (2007), and Sedelius and Linde (2017) whose detailed empirical analysis of semi-presidential types in European contexts shows that president-parliamentary systems are considerably more vulnerable to weaker democratic performance, democratic breakdown, and greater autocratization under conditions of divided government than premier-presidential systems, which display greater institutional resilience and adaptability in managing executive dualism.

Findings from studies focused primarily on internal or endogenous determinants demonstrate a consistent correlation between democratic development and the parliamentarized type of semi-presidentialism, particularly in Central and Eastern Europe, where most countries have successfully completed democratic transitions and integrated into Euro-Atlantic political and institutional structures. In contrast, numerous semi-presidential states – especially those with non-parliamentarized but presidentialized or balanced arrangements in Africa, Eastern and Southeastern Europe, and Asia – continue to record low levels of democratic performance and are often classified as hybrid or even autocratic regimes. This pattern is especially evident in several Eastern European countries, notably Georgia, Moldova, and Ukraine, which remain trapped in protracted, incomplete, or never-ending political transitions,⁽⁶⁾ oscillating between democratic opening and autocratic relapse. Such cases suggest that the limited effectiveness of semi-presidentialism in fostering democratic transition and consolidation stems not only from internal institutional and political dynamics (Lytvyn 2023) but also from exogenous structural pressures, including social, political, and economic instability and crises, geopolitical confrontations, and severe external shocks such as civil or interstate wars and armed conflicts (Boin, ’t Hart 2012; Gunitsky 2014; Hegre 2014; Sedelius et al. 2024; Yan 2023). This body of work is, however, concentrated on institutional interactions in normal times and often uses samples dominated by European cases. Instead, cases of semi-presidentialism outside Europe (in Africa, Asia, and only parts of Eastern Europe) illustrate that identical constitutional texts can produce divergent outcomes depending on party systems, informal power structures, economic stress, international pressures, and other contextual variables.

Two key implications emerge from the preceding analysis. First, treating semi-presidentialism as a single, uniform category risks overlooking critical variation: differences in constitutional design, de facto political power distribution, party configurations, and mechanisms of executive responsibility must be examined jointly to understand the system’s impact on democratic outcomes. Second, a focus solely on endogenous institutional factors may overstate institutional resilience, as exogenous shocks – such as armed conflicts, interstate wars, or severe crises – can rapidly alter power relations, enhance presidential personalization, or accelerate autocratizing tendencies. In sum, the literature demonstrates that semi-presidentialism is a heterogeneous system whose effects on democratization or autocratization are contingent on institutional type, partisan dynamics, and broader contextual pressures (Lytvyn 2020; Lytvyn 2023; Sedelius, Linde 2017). Building on these insights, the following section examines how exogenous shocks, particularly war and armed conflict, interact with semi-presidential variants in nascent transitional states with hybrid regimes.

Theoretical and empirical analyses provide ample grounds to assert that contemporary political science lacks a consensus on the positive or negative effects – prospects and risks – of semi-presidentialism, as well as its implications for democratic transition or autocratization. This aligns with the view that the effects of semi-presidentialism should be assessed, categorized, and compared in their plurality, given that it represents a highly diverse and heterogeneous political system shaped by multiple internal (endogenous) and external (exogenous) factors. The analytical complexity is further deepened by the wide variety of contexts in which semi-presidentialism is applied and analyzed comparatively – such as regional location, initial conditions of institutional choice and implementation, political traditions, previous and current political regime types, historical experience, and state maturity. Within this framework, the issues addressed in the study are particularly pertinent. Despite a substantial body of research, the features and consequences of adopting and operating semi-presidentialism in nascent transitional states with hybrid regimes remain insufficiently explored and comparatively evaluated – both in terms of inter-institutional and political relations, and especially under conditions of wars, armed conflicts, crises, and other forms of exogenous shocks.

Accordingly, the study further explores both internal (endogenous) and, above all, external (exogenous) parameters that affect the operation, effectiveness, and stability of semi-presidentialism during political transitions in nascent states, most of which function under hybrid political regimes. The main emphasis is placed on how different features of semi-presidentialism shape the success or failure, as well as the prospects and risks, of completing – or at least advancing – the process of political transition and transforming hybrid regimes toward democracy or autocracy. In other words, the research focuses on the complex and multifaceted question of why democratic – or autocratic – development in hybrid regimes of nascent transitional states with semi-presidential systems often remains incomplete or uncertain.

This is a highly relevant and practically significant issue, as many states worldwide still fit these analytical criteria. Numerous current or historical examples of semi-presidentialism can be identified – such as Bosnia and Herzegovina, Cameroon, Mali, Moldova, Montenegro, North Macedonia, Serbia, Taiwan, and Ukraine; to a lesser extent Bulgaria, Croatia, and Romania; and earlier cases such as Armenia, Georgia, Turkey, the Weimar Republic, and Yugoslavia – where political transitions remain incomplete or never-ending. In many of these countries, political regimes have been or continue to be hybrid due to a combination of factors, primarily internal or endogenous ones, such as political and inter-institutional dynamics. At the same time, many of these and other semi-presidential states (e.g., Armenia, Azerbaijan, Cameroon, Chad, Croatia, Georgia, Haiti, Mali, Moldova, Mozambique, Serbia [Yugoslavia], Sri Lanka, Ukraine, and Yemen at different periods) have also faced wars, armed conflicts, crises, and broader exogenous shocks. This demonstrates that, despite its potential risks and shortcomings, semi-presidentialism continues to be chosen for its flexibility (often absent in presidentialism) and its relative stability (sometimes lacking in parliamentarism), as well as due to the motives and strategic interests of political leaders. The most complex rationales for adopting semi-presidentialism – and the most challenging cases – typically arise in nascent transitional states with hybrid regimes. This underscores the need to identify, examine, and systematize both the positive (prospects) and negative (risks) features and effects of semi-presidentialism within the specific context of nascent transitional states, hybrid regimes, wars, armed conflicts, crises, and other exogenous shocks.

A range of external or exogenous factors – such as social and economic conditions, geopolitical tensions, interstate and domestic conflicts, major shocks and upheavals, civil and interstate wars, as well as broader non-institutional influences – can significantly amplify the negative or risky (though potentially also positive or promising) effects of semi-presidentialism. These factors may hinder or, in some cases, facilitate its operation when interacting with internal or endogenous dynamics, particularly in nascent transitional states with hybrid political regimes. This assumption remains valid, as many semi-presidential transitional states across different regions have experienced, or continue to experience, wars and armed conflicts triggered by social and economic crises or by ethnic, ethnolinguistic, religious, and geopolitical disputes. The impact of such armed conflicts, crises, and broader exogenous shocks often undermines the operation of semi-presidential systems, intensifying the personalization of power and, consequently, obstructing or reversing democratic transition. However, in specific cases, these same pressures may also create conditions that foster reform or institutional adaptation.

For example, Sedelius et al. (2024) highlight mainly negative trends regarding the impact of crisis-related exogenous factors on the operation of semi-presidentialism in Ukraine, noting increased personalization and presidentialization amid active military processes following the full-scale Russian-Ukrainian war in 2022. Ukraine entered the full-scale war (and, more generally, during 2014–2021) with an institutional and political – endogenous – configuration of balanced semi-presidentialism, in which the powers of the president and the prime minister in domestic, foreign, and defense policy partially overlapped and were broadly comparable. However, between 2019 and 2021, the president significantly outpowered the prime minister and the government, primarily due to endogenous institutional and political factors. These included substantially greater popular legitimacy and single-party parliamentary majority support – a situation unprecedented in the country’s recent history. The outbreak of war and the imposition of martial law – the main exogenous factors – combined with the consolidation of power around the presidency, further strengthened his influence. As a result, the president gained near-complete control over domestic and foreign policy and the functioning of government, often diminishing parliament’s role and at times bypassing procedural norms. While these measures were and remain necessary for defense and national unity, they have simultaneously caused substantial harm to democracy, notably by reducing democratic indicators, halting the democratic transition, and accelerating autocratization – thus complicating prospects for post-war re-democratization and democratic consolidation.

In contrast, less negative and even positive effects of crises and exogenous shocks on the operation of semi-presidentialism have been observed in other states. For instance, in Georgia and Moldova (and to some extent in Armenia, Croatia, and Serbia), the discourse of war coincided with the strengthening of the presidency and some personalization of power. However, these states managed to avoid full autocratization and even achieved relatively higher levels of democracy during or after armed conflicts. Similarly, Yan (2023), studying semi-presidential Taiwan during the exogenous shock of the Covid-19 pandemic, demonstrated that semi-presidentialism can function effectively amid crises. For this, the power needs to be clearly and organically divided between the head of state and the head of government through well-regulated endogenous (institutional and political) arrangements. Overall, these cases support the view that semi-presidentialism can be both an effective and a risky mechanism for democratization in crisis or post-crisis contexts of exogenous shocks.

Given this, and to improve the analytical precision of the study, particular attention should be paid to the concepts and parameters used to theorize and empirically assess the external (exogenous) factors that influence the choice, operation, and outcomes of semi-presidentialism. These factors primarily include wars and armed conflicts, as well as geopolitical and international crises – forms of exogenous shocks that shape institutional and political development in nascent transitional states. Such conditions become especially critical when they interact with internal (endogenous) weaknesses of semi-presidential systems, such as ambiguous institutional design, imbalanced inter-institutional relations, hybrid regime structures and dynamics, incomplete or shifting political transitions, limited regime consolidation, or the young age and limited statehood experience of the country.

In this research, the most critical situations arise when a nascent transitional state with a hybrid regime and a semi-presidential system – already affected by complex inter-institutional and political relations, ongoing democratic reforms, and other internal (endogenous) factors – encounters a crisis-prone external (exogenous) environment shaped by adverse international conditions, particularly war or armed conflict. Under such circumstances, external shocks can evolve into systemic crises that endanger the core values and essential functions of the political and even broader social system, requiring urgent and often extraordinary measures implemented under severe pressure and uncertainty (Boin, ’t Hart 2012).

It is most likely that the operation of semi-presidentialism in transitional states with hybrid regimes becomes particularly affected when a state enters an internal or interstate war, whether against another state or non-state entities. During wartime, states typically centralize resources and decision-making processes to maximize efficiency and ensure rapid response, which is politically and functionally justified. However, such centralization frequently results in the personalization of power, often manifested as presidentialization. In these circumstances, political elites and even society tend to rally around a key or authoritative leader and institution – usually the head of state (president) or, in certain configurations, the head of government (prime minister). From the perspective of political utility, this behavior is understandable, as armed conflicts require swift coordination and unambiguous command. Yet this concentration of authority can simultaneously weaken democratic checks, reduce pluralism, and, in extreme cases, foster autocratization. Within semi-presidential systems – especially those embedded in hybrid regimes and incomplete political transitions – this dynamic poses a particularly serious risk to democratic resilience.

Given this, the study identifies two complementary scenarios illustrating how semi-presidential systems respond to crises and broader exogenous shocks, depending on their institutional design and regime characteristics. These scenarios do not concern the adoption of semi-presidentialism as a crisis response – since all examined states already operate within this framework – but rather its operation and transformation under conditions of acute external stress. Notably, different types of semi-presidentialism may shape elite consolidation, societal cohesion, and power distribution in distinct ways during crises (Åberg 2020; Åberg, Denk 2020; Åberg, Denk 2024; Åberg, Sedelius 2020; Frye 1997; Jung, Deering 2015). In certain contexts, crisis-induced pressures may foster temporary power-balancing or inter-institutional coordination, whereas in others they can intensify power concentration and accelerate regime closure.

Scenario 1: Resilient (cooperative or power-sharing) semi-presidentialism during crises and broader exogenous shocks. This scenario corresponds mainly to premier-presidential – parliamentarized or even balanced – types, where the constitutional and political distribution of power between the president and the prime minister remains functionally coordinated or even relatively balanced. Endogenous institutional checks and inter-institutional cooperation are preserved. Exogenous shocks (wars, armed conflicts, or crises) may provoke temporary centralization of authority, but the system’s internal design enables adaptive responses and constrains excessive personalization of power. Hybrid regimes (or electoral democracies) may therefore experience short-term centralization of power yet preserve medium-term democratic processes and resilience (Frye 1997; Jung, Deering 2015; Gunitsky 2014; Houle, Kayser 2019). The “rally-around-the-flag” effect (Devine et al. 2020; Kassop 2003; Sedelius et al. 2024) may temporarily strengthen popular support for key political institutions and leaders, facilitating elite unity and societal cohesion without long-term autocratization. A relevant example is Ukraine (2014–2019 and partly 2019–2022), where institutional cooperation and shared executive authority helped sustain democratic accountability under conditions of war and external aggression (Choudhry et al. 2018; Hale and Orttung 2016; Sedelius et al. 2024).

Scenario 2: Vulnerable (conflictual or power-concentrating) semi-presidentialism during crises and broader exogenous shocks. This scenario typically corresponds to president-parliamentary – presidentialized or even balanced – types, where endogenous institutional factors already favor the presidency, such as superior legitimacy, party dominance, or weakened parliamentary counterweights. Exogenous shocks (wars, armed conflicts, or severe crises) amplify these asymmetries and imbalances, triggering presidentialization, strong personalization of power, and inter-institutional erosion. Hybrid regimes under such conditions often experience democratic backsliding, interrupted transitions, or even autocratization. The cases include Ukraine (2022–present) and, to varying degrees, Armenia and Cameroon during specific historical periods (Markarov 2016; Sedelius et al. 2024). These examples demonstrate that the type of semi-presidentialism – ranging from premier-presidential and mainly parliamentarized or balanced to president-parliamentary and mainly presidentialized – crucially conditions regime resilience or vulnerability during crises and broader exogenous shocks.

Taken together, these scenarios highlight that the outcomes of semi-presidentialism under exogenous shocks are not predetermined but conditional upon the interaction between institutional design and crisis dynamics. The same external stressors may either reinforce executive cooperation and democratic resilience or accelerate power concentration and regime deterioration. The key determinant lies in whether semi-presidential arrangements function as mechanisms of power-sharing and mutual accountability or as frameworks enabling dominance and personalization when confronted with war, conflict, or systemic crisis.

Ultimately, this implies that wars and armed conflicts – as the most intense forms of crises and broader exogenous shocks – substantially increase the significance of both institutional design (internal or endogenous factors) and non-institutional (external or exogenous) conditions for the operation and outcomes of semi-presidentialism, particularly within political transitions and hybrid regimes. Given this, the study emphasizes the necessity of conceptual precision regarding the terms war and armed conflict. Following established literature (ICRC 1949; Balendra 2008; Levy 1983; O’Connell 2008; Vité 2009), interstate armed conflicts involve confrontations between states or high contracting parties that include territorial occupation, engagement of armed personnel, or other forms of significant hostilities. War represents a narrower but more severe category of armed conflict, typically marked by organized armed forces, large-scale military operations, high casualty levels, and far-reaching domestic and international consequences (Levy 1983: 51; Singer 1970; Vasquez 1993).⁽⁷⁾ From a definitional standpoint, the concept of armed conflict is therefore broader and more inclusive than war, allowing for the examination of a wider range of cases relevant to semi-presidentialism.

We thus treat armed conflicts and wars as components of the broader concept of crisis or exogenous shock. Armed conflicts are understood as a subset of crises – exogenous shocks that directly influence political and institutional dynamics in semi-presidential systems. Wars and armed conflicts, in this sense, underscore the intricate interplay between endogenous (institutional) and exogenous (non-institutional) dimensions of political development and the dynamics of semi-presidentialism. The internal institutional design of semi-presidentialism – its constitutional architecture, the balance of political authority between president and prime minister, and mechanisms of inter-institutional relations – conditions how states respond to and depend on these external pressures. Premier-presidential – mainly parliamentarized or balanced – configurations tend to mitigate negative consequences by preserving executive coordination and preventing the excessive personalization of power, thereby supporting democratic resilience. Conversely, president-parliamentary – mainly presidentialized or otherwise unbalanced – configurations are generally more vulnerable to power concentration and institutional erosion, heightening the risk of presidentialization and autocratization (Åberg, Denk 2024; Åberg, Sedelius 2020; Sedelius, Linde 2017; Sedelius et al. 2024).

Political and institutional variables also shape states’ international behavior under conditions of crisis, war, or armed conflict.⁽⁸⁾ Within semi-presidential systems – as in other systems of government – these tendencies are mediated by institutional design. President-parliamentary systems (alongside presidential or broadly presidentialized systems), characterized by concentrated executive authority and weaker institutional constraints, tend to display a higher propensity to initiate or engage in warfare and to pursue assertive or unilateral foreign policies (Albalate et al. 2012; Amorim Neto, Accorsi 2022: 150–159; Kroenig, Schramm 2021). By contrast, premier-presidential systems (as well as parliamentary or more parliamentarized systems), which feature a more balanced distribution of executive power, are generally associated with cooperative or moderate external engagement and exhibit the highest degree of pacifism (Reiter, Tillman 2002: 820–824). However, Leblang and Chan (2003: 391–398) report no significant cross-systemic differences in international behavior, including the likelihood of war initiation or participation.

Overall, these theoretical and empirical insights highlight that the risks and prospects of semi-presidentialism depend on the interaction between endogenous institutional structures and exogenous shocks such as wars or armed conflicts. Such crises amplify the importance of institutional resilience, elite cohesion, and societal mobilization, directly shaping democratic trajectories and the outcomes of political transitions. Moreover, the effects of semi-presidential design under exogenous shocks are also mediated by the broader socio-economic environment, which conditions state capacity, governance performance, and the ability of institutions to absorb political stress. Existing research shows that economic development, inequality, and government effectiveness significantly shape regime resilience and democratic outcomes across different systems of government, including semi-presidential ones (Acemoglu, Robinson 2005; Przeworski et al. 2000; Persson, Tabellini 2002). Accordingly, socio-economic indicators constitute an integral part of the theoretical framework for evaluating the risks and prospects of semi-presidentialism in transitional states exposed to armed conflict. By integrating both endogenous and exogenous perspectives, this analytical background provides a comprehensive foundation for understanding the operation, adaptability, and vulnerabilities of semi-presidentialism in nascent transitional states with hybrid regimes affected by armed conflict. This conceptual grounding further establishes the necessary link to the methodological framework of the study, which operationalizes these categories into measurable variables. The following section, therefore, outlines the methodological approach, case-selection criteria, and analytical procedures employed to examine how different types of semi-presidentialism influence political resilience and regime outcomes under conditions of crises or broader exogenous shocks.

This section presents the methodological framework of the study, operationalizing key analytical categories – types of semi-presidentialism, hybrid regime dynamics and configurations, and forms of crises or exogenous shocks (wars and armed conflicts) – into a coherent system of variables suitable for comparative assessment. The design combines qualitative and statistical-comparative approaches to examine how different institutional and political configurations of semi-presidentialism influence state effectiveness, regime stability, democratic trajectories, and broader political transition under crisis conditions. The focus is on nascent transitional states with hybrid regimes under semi-presidential systems, reflecting both endogenous institutional and political dynamics (constitutional design and executive–legislative relations) and exogenous pressures from armed conflicts, which shape short-term responses and long-term outcomes. The goal is to translate core concepts into operational indicators and specify case selection logic, methodological tools, and analytical procedures.

The preceding sections highlighted the variability of systems of government and the heterogeneity of semi-presidentialism as a distinct institutional type. Empirical evidence shows both strengths and vulnerabilities of semi-presidential systems in democratization, regime transformation, and political dynamics. Building on this, the forthcoming comparative and statistical analysis applies a trichotomous classification of political systems – presidential, semi-presidential, and parliamentary – following Elgie’s (1998) approach. Semi-presidential systems are further categorized according to the typologies of Shugart and Carey (1992) and Elgie (2011). The selected analytical cases differentiate semi-presidentialism along two dimensions: (1) institutional type and categorization – president-parliamentary vs premier-presidential, reflecting formal inter-institutional relations and government responsibility; and (2) functional or political type and categorization – presidentialized, parliamentarized, or balanced, reflecting the practical distribution of power and patterns of political dominance.

All cases are analyzed institutionally and politically, focusing on the degree and patterns of conflict within the dual executive and between branches of power. Previous studies measure intra-executive conflict, emphasizing institutional and behavioral dimensions (Protsyk 2005; Protsyk 2006; Sedelius, Ekman 2010; Sedelius, Mashtaler 2013). However, most of them concentrate primarily on the president–prime minister dyad, but often overlook the role of parliaments. This study adopts a broader analytical triangle – president–prime minister–parliament – to evaluate intra-institutional tensions and coordination.

This is operationalized using types or phases of semi-presidentialism from Skach (2007) and Lytvyn and Romanyuk (2021). Six types – fully unified majority, partially unified majority, fully unified minority, partially unified minority, divided majority, and divided minority – represent an ascending scale of conflict intensity within the executive dualism and across the branches of power. This typology allows systematic comparison of conflict levels and institutional stability across cases.

The hybridity of political regimes and the degree of democratization or autocratization is measured using Freedom House’s Freedom in the World (FiW) and the Polity projects. FiW scores political rights and civil liberties, categorizing states as “free,” “partly free,” or “not free,” using both 100-point and 7-point scales (Freedom House n.d.a; Freedom House n.d.b). Polity assesses executive recruitment, constraints on the executive, and political participation, scoring political regimes from –10 to +10 (Marshall, Gurr 2020; Polity5 Project 2018). Democracies score +6 to +10, closed and open anocracies (as hybrid regimes) –5 to +5, and autocracies –6 to –10, with additional codes for failed states (–66, –77, –88). Both projects are employed complementarily to ensure conceptual robustness and empirical breadth. Consequently, only “partly free” or anocratic states are included, as they represent hybrid regimes within transitional contexts.

An essential selection criterion is that the semi-presidential state must have experienced or be experiencing war or armed conflict, identified above and using recognized international datasets, including the Correlates of War Project (n.d.) and the Major Episodes of Political Violence database (Center for Systemic Peace n.d.). Both active and frozen conflicts are included. Frozen conflicts refer to situations when hostilities have ceased, but the underlying political disputes remain unresolved (Perry 2009). Frozen conflicts thus remain analytically relevant due to ongoing political instability and institutional stress. The study covers 14 historical and ongoing cases (Table 1), forming the analytical dataset for comparing semi-presidential configurations under armed conflicts.

The selected cases vary geographically, socio-economically, and in conflict type and duration, providing valuable heterogeneity for analyzing institutional and political patterns across diverse crisis environments. The aim is therefore not to standardize all conditions or control for all structural variation but to identify consistent trends and trajectories in how different types of semi-presidentialism respond to exogenous shocks. Case selection follows a most-different-systems logic: all cases combine semi-presidential design with hybrid regime characteristics and exposure to armed conflict, while differing in secondary attributes, allowing evaluation of robustness, direction, and dynamics of institutional, political, and socio-economic dynamics under stress. The temporal coverage ends in December 2024, enabling the analysis to trace not definitive outcomes but the trajectory of potential regime transformation driven by armed conflicts and broader exogenous pressures.

The analysis thus incorporates not only political and institutional variables but a range of socio-economic indicators. Socio-economic factors – GDP per capita, Gini coefficient (income inequality), Human Development Index (HDI) (United Nations Development Programme n.d.), Worldwide Governance Indicators (particularly Government Effectiveness, GE) (World Bank Group n.d.), and Economic Freedom of the World Index (Fraser Institute n.d.) – capture the context in which semi-presidential systems operate. Research shows that socio-economic performance interacts with political systems and institutional designs, influencing stability and resilience in states with hybrid regimes (Acemoglu, Robinson 2005; McManus, Ozkan 2018; Przeworski et al. 2000; Persson, Tabellini 2002). Accordingly, socio-economic indicators condition not only the operation of semi-presidential institutions but also their capacity to withstand the stresses produced by armed conflicts. These variables account for external pressures and resource constraints that may moderate the impact of semi-presidential design on political outcomes, especially under armed conflict.⁽⁹⁾

The analytical framework, therefore, incorporates a three-tier structure of variables. First, the independent variables represent institutional and political characteristics of semi-presidentialism, including the formal type (premier-presidential vs president-parliamentary) and the actual type and functional distribution of power (presidentialized, parliamentarized, and balanced configurations). Second, socio-economic indicators – GDP per capita, income inequality (Gini coefficient), HDI, Government Effectiveness (GE), and the Economic Freedom of the World Index – serve as control variables that capture structural capacities and constraints shaping the performance of political systems and institutions under crisis. Third, the outcome variables evaluate hybrid regime trajectories and executive–legislative functioning through indicators of democratic or autocratic performance, institutional stability, and levels of intra-executive and inter-institutional conflict. This structure enables a more precise assessment of how institutional design interacts with contextual pressures, shaping political resilience and effectiveness under armed conflicts. Importantly, outcome variables are not treated as controls but constitute a distinct category focused on evaluating regime performance and institutional or political behavior of semi-presidentialism under crisis.

On this basis, the selected cases and dataset provide the empirical foundation for a mixed-method comparative analysis – primarily statistical (correlational), complemented by qualitative insights – to test the study’s central hypothesis. At the same time, the analysis acknowledges the inherent limitations of this design: the relatively small-N dataset and contextual variation constrain the degree of causal generalization possible. Therefore, the findings should be interpreted as identifying robust correlations and recurring institutional and political dynamics rather than strict causality.⁽¹⁰⁾ These limitations are mitigated through the complementary use of qualitative insights across multiple sources of data.

Rather than attempting causal identification through large-N econometric modelling, the statistical component of the research design is focused on identifying correlations and patterned differences between distinct types of semi-presidentialism. As scholars note, limited case numbers, data discontinuities (uneven temporal coverage), and structural heterogeneity constrain the feasibility and interpretive validity of strict causality approaches in studies of regime trajectories under conflict and transition (Flores, Nooruddin 2009; Gerring 2012; Gledsch, Ruggeri 2010; Lieberman 2005). These concerns are particularly relevant for research on hybrid regimes exposed to armed conflicts, where institutional destabilization and disruptions of political capacity produce severe data discontinuities and conceptual non-equivalence across cases. This highlights the importance of focusing on patterned associations and contextual mechanisms rather than attempting to establish causality. To strengthen the robustness of the analysis and mitigate potential overinterpretation, the statistical assessment is complemented by longitudinal and qualitative components. This approach considers year-by-year trajectories of democratic performance, as well as institutional stability, across selected states, capturing short-term fluctuations, reversals, and recoveries. It incorporates concise, context-sensitive case comparisons, enabling a more nuanced understanding of the dynamic interplay between institutional configurations, domestic political conditions, and exogenous shocks.

Grounded in this theoretical framework, the hypothesis seeks to determine whether, and in what direction, different types of semi-presidentialism shape political resilience and democratic outcomes in nascent transitional states with hybrid regimes affected by armed conflict. It posits that: 1. President-parliamentary systems exhibit lower levels of democracy (or higher autocracy) and fewer intra-executive or institutional conflicts– in both the president–prime minister executive dyad and the president–prime minister–parliament triangle – compared to premier-presidential systems; 2. Presidentialized and balanced semi-presidential systems are more prone to democratic backsliding and socio-economic decline under armed conflict than parliamentarized variants. However, presidentialized systems – due to more centralized executive authority – may reduce institutional conflict and support short-term political stability compared to parliamentarized and, especially, balanced systems.

The empirical results will show how semi-presidential types influence trajectories of nascent transitional states with hybrid regimes – either facilitating democratization or driving autocratization – under armed conflicts and broader exogenous shocks.

This section analyzes how semi-presidential configurations influence political and socio-economic outcomes in nascent transitional states with hybrid regimes during wars, armed conflicts, and broader exogenous shocks. Structured data from multiple analytical indicators are used to identify patterns in development performance, governance, and regime dynamics, as well as to compare different types and categorizations of semi-presidentialism. The analysis is structured around three main analytical dimensions: (a) socio-economic outcomes under armed conflict, (b) democratic and autocratic performance of hybrid regimes, and (c) intra-executive and inter-institutional conflict within semi-presidential systems. Each dimension compares categorizations and types of semi-presidentialism, emphasizing hypothesized patterns and evaluating their effects on socio-economic, democratic, and institutional outcomes under armed conflict. The section thus explicitly tests the hypotheses regarding the differential impact of president-parliamentary vs premier-presidential systems, and of presidentialized, balanced, and parliamentarized forms of semi-presidentialism. This approach directly reflects the theoretical scenarios of resilient versus vulnerable semi-presidentialism, linking institutional design to expected outcomes under armed conflicts and broader exogenous shocks.

Socio-economic measures indicate that nascent transitional semi-presidential states are sometimes able to maintain or even enhance economic performance during armed conflicts and other exogenous shocks. In the majority of states within the analytical sample, GDP per capita, Human Development Index (HDI), and economic freedom exhibit measurable improvement, while income inequality (Gini coefficient) shows a declining trend. These dynamics, however, are not uniformly stable and may fluctuate over specific periods. Comparable variability is observed in democratic and autocratic performance, as captured by Freedom in the World (FiW) and Polity project indices, reflecting general declining democratic outcomes across many sampled states with diverse political regimes. Collectively, these observations – from the onset of armed conflict (the first analytical year) to its conclusion, or to the most recent year in cases of unresolved hostilities (the last analytical year for each state) – underscore the complex interactions among regime type, armed conflict, and socio-economic development in semi-presidential systems (Table 2).

Considering the heterogeneous nature of semi-presidential systems, the analysis focuses on comparing socio-economic and political/democratic indicators across different types and categorizations of semi-presidentialism. Table 3 illustrates that in Categorization 1 – based on formal institutional indicators, particularly whether the government is collectively responsible to parliament alone or also to the president – premier-presidential systems generally achieve better outcomes than president-parliamentary systems. Only government effectiveness (GE) from the Worldwide Governance Indicators (WGI) is similar across both types. President-parliamentary systems mainly occur in fully unified majority configurations, whereas premier-presidential systems are associated with partially unified majority configurations, suggesting higher stability for the latter.

In Categorization 2 – based on both formal and actual indicators, particularly regarding the source of political leadership – states with balanced semi-presidentialism show, on average, the highest socio-economic and political/democratic scores. This is paradoxical given that previous studies (Elgie 1999; Sedelius 2006) often consider balanced semi-presidentialism the least stable institutional and political type for regular politics. During wartime, balanced semi-presidentialism thus would be expected to perform even worse – yet this is contradicted. Parliamentarized semi-presidential systems, commonly regarded as the most successful model, outperform presidentialized and balanced types only in democratic indicators, not in socio-economic development. Presidentialized systems tend to correspond with fully unified majority configurations, while balanced and parliamentary systems align with partially unified majority configurations, which are more conflict-prone (see Table 3).

Comparable results regarding Categorization 1 of semi-presidentialism – its distinction between president-parliamentary and premier-presidential types – are confirmed through a detailed analysis. Variations in the levels of the examined indicators between these two institutional types are statistically validated using the Mann–Whitney U test (Table 4). The premier-presidential type exhibits consistently stronger performance in terms of democratic quality, as indicated by the referenced FiW and Polity scores, and higher economic development, particularly in GDP and economic freedom, compared to the president-parliamentary type.

Similar results emerge from the analysis of Categorization 2 of semi-presidentialism, which differentiates between presidentialized, balanced, and parliamentarized types. Based on the Kruskal–Wallis test applied to the same analytical indicators, presidentialized cases generally display lower political, democratic, and socio-economic scores than the other two types. This pattern is particularly evident in the indicators of democratic quality of regimes from the FiW and Polity projects, as well as in measures of economic freedom and human development. Notably, balanced semi-presidentialism often performs at least on par with, and in some cases surpasses, the parliamentarized type. For instance, balanced configurations record higher levels of economic freedom than both presidentialized and parliamentarized variants (Table 5).

At the same time, it is analytically useful to examine in greater detail the dynamics of political regimes and the levels or types of intra-executive and inter-institutional conflict across different categorizations of semi-presidentialism in transitional states with hybrid regimes under armed conflicts. The analysis focuses on the percentage distribution of country-years related to distinct regime dynamics (Table 6) and to various levels of intra-executive and inter-institutional conflict (Table 7), disaggregated by both categorizations of semi-presidentialism and its respective types. To facilitate cross-comparison of regime dynamics according to the FiW and Polity projects, all analyzed cases are further classified into three groups: (a) those exhibiting a more democratic trajectory of hybrid regimes (consistently or intermittently scoring between 3 and 3.5 points on FiW and between +5 and +9 on Polity); (b) those demonstrating uncertain or fluctuating hybrid regime dynamics (typically scoring between 4 and 4.5 on FiW and from 0 to +4 on Polity); and (c) those characterized by a more autocratic trajectory of hybrid regimes (consistently or intermittently scoring 5 or more points on FiW and between –5 and –1 on Polity).

As shown in Table 6, identifying unambiguous trends remains challenging, as both premier-presidential and president-parliamentary types of semi-presidentialism display broadly comparable proportions of democratic tendencies in the evolution of hybrid regimes. Nevertheless, president-parliamentary systems and presidentialized configurations of semi-presidentialism are most frequently associated with the autocratization of hybrid regimes. In contrast, balanced and, particularly, parliamentarized semi-presidential systems demonstrate a substantially higher incidence of democratizing tendencies. Yet, in several deviant cases, balanced and presidentialized types surpass others in the share of more democratic tendencies while simultaneously lagging behind in the proportions of conditionally uncertain and more autocratic dynamics.

In turn, with respect to the determination of the type and level of conflict intensity (Table 7), the findings indicate that systems with fully or partially unified majorities – and consequently lower levels of intra-executive and inter-institutional conflict (and, therefore, higher institutional stability) – are typical of president-parliamentary and presidentialized variants of semi-presidentialism. By contrast, systems characterized by divided majorities or divided minorities – and, hence, higher levels of intra-executive and inter-institutional confrontation (and correspondingly lower institutional stability) – occur more frequently among premier-presidential types of semi-presidentialism, particularly within the parliamentarized and balanced designs. Notably, armed conflicts tend to originate in states with semi-presidential arrangements that are less conflict-prone and institutionally more stable – precisely those most commonly represented in the analytical sample of nascent transitional semi-presidential states exposed to exogenous shocks (Tables 1 and 7).

Taken together, these findings provide a solid basis for asserting that premier-presidential type, on the one hand, and parliamentarized as well as balanced forms of semi-presidentialism, on the other, exposed to armed conflicts and broader exogenous shocks, demonstrate markedly stronger socio-economic, political, and democratic performance than, respectively, president-parliamentary and presidentialized variants. At the same time, the overall differences among the results across types are generally modest in most cases of semi-presidentialism, primarily due to the shared developmental constraints of nascent transitional states operating under crisis conditions. Nevertheless, the direction and trajectory of change from this common baseline may prove crucial for the longer-term evolution and outcomes of different semi-presidential configurations.

To further substantiate and verify the preceding conclusions derived from statistical comparisons, a correlation analysis was conducted to examine the interrelations between socio-economic, political, and democratic indicators across different categorizations of semi-presidentialism – a method that allows for clearer and more robust inference. While the data already reveal several consistent and notable trends, particular attention was devoted to identifying and interpreting statistically significant relations among various types of semi-presidentialism, levels of inter-institutional conflict, and the corresponding socio-economic, political, and democratic indicators or variables. The correlation analysis produced several noteworthy findings. Specifically, the Spearman rank-order correlation matrix revealed a statistically significant association (p < 0.05) between higher levels of conflict among power institutions and higher scores on democratic quality and the Human Development Index (HDI). Furthermore, relatively elevated levels of government effectiveness were also observed in semi-presidential states exhibiting greater inter-institutional conflict intensity (Table 8).

At the same time, statistically significant relations are evident between the types of semi-presidentialism and indicators of political regime development. Specifically, the president-parliamentary type of semi-presidentialism is associated with substantially lower levels of democracy according to the FiW and Polity projects, in contrast to the premier-presidential type. Similar patterns emerge when examining the three types of semi-presidentialism within the alternative categorization: the presidentialized type displays weaker indicators of democratic development across both projects, while the level of democracy tends to increase with greater parliamentary orientation – that is, with the parliamentarization of semi-presidentialism. Moreover, parliamentarized and, to a certain extent, balanced semi-presidential systems exhibit higher socio-economic performance, with human development and economic freedom indicators that are noticeably stronger and more advanced than those observed in presidentialized systems (see Table 8).

Overall, the analyzed statistical data confirm the presence of meaningful correlations between the different types and categorizations of semi-presidentialism and, respectively, the levels of inter-institutional conflict, hybrid regime development, and socio-economic performance. In particular, premier-presidential systems (Categorization 1), as well as parliamentarized and balanced types (Categorization 2) of semi-presidentialism, tend to achieve stronger outcomes in fostering democratization and socio-economic progress during and after armed conflicts. These findings are largely consistent with the earlier statistical comparisons and general conclusions presented above. The results, therefore, support the hypothesis that presidentialized variants of semi-presidentialism are less effective in advancing democratization and socio-economic development under conditions of conflict compared to parliamentarized and balanced forms. Moreover, significant correlations emerge between higher levels of inter-institutional conflict and higher scores on democracy indices, human development, and governance effectiveness. Notably, balanced semi-presidential systems – somewhat paradoxically from a political science perspective – often perform on par with or even surpass parliamentarized systems. Taken together, these findings reinforce the established view that parliamentarized semi-presidential systems – especially those of the premier-presidential type – are more conducive to democratization and socio-economic advancement than their more presidentialized counterparts, particularly president-parliamentary systems.

From the perspective of the analytical cases and variables, as well as the results of statistical and correlational analysis, the identified relations merit further clarification. The significant association between presidentialized forms of semi-presidentialism and accelerated autocratization during or after armed conflict aligns with the institutional structure of these systems, which are usually president-parliamentary. In such systems, the president holds extensive powers over the government and, in some cases, over the parliament. Under conditions of armed conflict or broader exogenous shock, presidents often gain additional political and electoral support, especially in contexts of military success or rising nationalist sentiment. This tends to strengthen the concentration of power around the head of state and correlates with the risk of regime autocratization in presidentialized semi-presidential systems.

By contrast, the relatively higher democratic and socio-economic indicators observed in parliamentarized semi-presidential systems reflect their institutional design, which typically corresponds to the premier-presidential type. These systems grant stronger or even dominant powers to the parliament, particularly in forming and holding the government responsible. Finally, the stability or improvement of democratic and socio-economic indicators in balanced semi-presidentialism may be linked to the adaptive behavior of the dual executive. Faced with the risk of intra-executive and inter-institutional conflict during war, political actors may be more inclined to coordinate their actions and cooperate, reducing institutional confrontation and maintaining equilibrium under stress. Overall, the observed patterns largely confirm the hypothesized differences, while also highlighting unexpected strengths of balanced semi-presidentialism under armed conflicts.

To complement the cross-sectional statistical analysis and address the limitations inherent in purely correlational inference, temporal trajectories of democratic or autocratic and institutional development were examined. This longitudinal approach tracks year-by-year changes in FiW and Polity scores across selected semi-presidential states affected by armed conflicts, capturing both overall trends and short-term reversals or recoveries. By analyzing these dynamics, the study clarifies whether the observed associations reflect sustained patterns of institutional resilience or transient fluctuations induced by wartime pressures. The full empirical dataset comprises 176 country-year observations covering semi-presidential states with hybrid regimes under conditions of armed conflict. For each observation, socio-economic and governance indicators (HDI, GDP per capita, Economic freedom index, Gini coefficient, WGI (GE)) were systematically integrated with political regime measures (FiW, Polity) as well as metrics of intra-executive and inter-institutional conflict intensity.

The dataset enables comparison across both the Shugart and Carey (1992) and Elgie (2011) categorizations of semi-presidentialism, allowing parallel analysis of president-parliamentary versus premier-presidential systems, as well as presidentialized, balanced, and parliamentarized forms. Year-by-year trajectories of FiW and Polity scores were plotted for selected representative cases to complement cross-sectional tests. These trajectories reveal short-term declines and recoveries that correlations may mask, facilitating the distinction between sustained institutional trends. A comparative overview of several cases with varying semi-presidential configurations and conflict histories further illustrates these dynamics, highlighting contrasting patterns of democratic performance over time.

For instance, Armenia (2007–2018) and Moldova (1991–2000), both operating under premier-presidential frameworks (initially or subsequently balanced), exhibit moderate wartime declines in FiW and Polity indicators, followed by post-conflict and even in-conflict recovery, suggesting adaptive institutional mechanisms. A similar trajectory may be anticipated for Ukraine (since 2014), which initially had a balanced and later a presidentialized premier-presidential system, showing democratic erosion during war. In contrast, other premier-presidential systems – primarily presidentialized or less frequently balanced – did not demonstrate such recoveries (e.g., Chad (2005–2010), Georgia (2013–2024), Haiti (2020–2024), Mali (2012–2022)), failing to achieve post-conflict or in-conflict democratization. Likewise, Cameroon (2017–2024), Croatia (1991–1995), Mozambique (2017–2024), Russia (1994–2000), Sri Lanka (1983–1993, 2005–2009), and Yemen (1994–2011), characterized by presidentialized semi-presidentialism in a president-parliamentary structure, experienced steep democratic downturns and prolonged concentration of executive power, consistent with the earlier statistical findings. These patterns persisted both during and after armed conflicts. Conversely, Armenia (1991–2007) and Sri Lanka (1994–2004) exhibited relatively balanced institutional performance despite recurring conflicts under a president-parliamentary structure, highlighting the stabilizing potential of coordinated dual-executive arrangements. The only notable exceptions were Azerbaijan in the early 1990s and Georgia during 2004–2012.

These illustrative vignettes indicate that temporal patterns vary across cases, and that contextual factors – such as timing and intensity of armed conflict, as well as domestic political conditions – play a critical role in interpreting cross-sectional correlations. Descriptive evidence suggests that some premier-presidential and balanced cases achieve partial post-conflict recovery in democratic indices, whereas presidentialized cases experience prolonged declines. Given the small-N nature of the dataset and uneven temporal coverage, these comparisons primarily identify patterned associations and plausible contextual mechanisms rather than establishing causal inference.

The empirical findings align with the theoretical scenarios. Premier-presidential and balanced or parliamentarized types of semi-presidentialism tend to preserve inter-institutional cooperation and democratic resilience, while president-parliamentary and presidentialized forms exhibit greater tendencies toward power concentration and institutional vulnerability under armed conflicts. Taken together, both the cross-sectional and temporal analyses indicate that the relations between semi-presidential configurations, inter-institutional conflict levels, political and socio-economic outcomes, and regime trajectories unfold dynamically over time, rather than being confined to single-year correlations. Incorporating both longitudinal and case-oriented perspectives, therefore, enhances the robustness and interpretive depth of the findings. These results underscore that semi-presidentialism’s impact on hybrid regime stability and socio-economic outcomes is conditional on the interaction between institutional design and exogenous shocks, demonstrating the relevance of distinguishing between resilient and vulnerable scenarios in both theoretical and empirical analyses.

The conducted study allows for several general conclusions regarding the significance of semi-presidentialism under conditions of political transition and armed conflicts in nascent states with hybrid regimes.

First, the results of the comparative, statistical, and longitudinal analyses confirm that semi-presidentialism is not a homogeneous institutional design. Its different types – president-parliamentary versus premier-presidential in one categorization, and presidentialized, balanced, and parliamentarized in another – exhibit distinct patterns in their impact on political stability, democratic or autocratic performance, and socio-economic development. Premier-presidential and parliamentarized systems consistently demonstrate stronger resilience, maintaining or recovering democratic indicators, human development, and economic freedom even under conditions of armed conflict or broader exogenous shocks. Conversely, president-parliamentary and presidentialized variants more frequently experience democratic erosion, autocratization tendencies, and slower socio-economic recovery during crises.

Second, the influence of semi-presidentialism on democratic and socio-economic trajectories in hybrid regimes is highly contingent upon the interaction between endogenous (institutional, political) factors and exogenous (non-institutional) shocks. Systems with higher degrees of intra-executive and inter-institutional conflict, paradoxically, often achieve better democratic outcomes, suggesting that institutional competition and power-sharing mechanisms can promote adaptive behavior and checks on excessive presidential authority. Balanced and parliamentarized semi-presidential systems, particularly those of the premier-presidential type, tend to sustain coordination under stress, reducing the risk of concentration of power and enabling partial post-conflict recovery of both democratic and socio-economic indicators. These findings are confirmed by both cross-sectional statistical comparisons and year-by-year longitudinal trajectories across 176 country-year observations.

Third, the analysis establishes statistically significant correlations between the types of semi-presidentialism, levels of intra-executive and inter-institutional conflicts, democracy indices, human development, and economic freedom. Higher levels of inter-institutional conflict correlate with improved democratic quality and governance effectiveness, indicating that dynamic interaction among executive centers can foster institutional resilience, democratic development, and socio-economic progress in transitional states exposed to armed conflict – especially in the absence of the president’s excessive concentration of power.

These findings guide institutional and political reforms in semi-presidential states facing incomplete political transition, in-conflict or post-conflict reconstruction, and broader socio-political crises. For example, in the Ukrainian context, the results suggest that promoting parliamentary empowerment and enhancing the role of the prime minister within a semi-presidential framework could strengthen democratic resilience and sustainable political development in the post-war period. Institutional safeguards that formalize power distribution, reinforce checks and balances, and limit personalization of executive authority are likely to contribute to both internal stabilization and alignment with democratic norms. Likewise, other nascent or transitional semi-presidential states may benefit from emphasizing power-sharing and balanced inter-institutional relations as a buffer against the destabilizing effects of armed conflict or broader external shocks.

Finally, this study reinforces the conceptual distinction between “resilient” and “vulnerable” semi-presidential scenarios. Resilient configurations – primarily premier-presidential, balanced, or parliamentarized systems – demonstrate the capacity to maintain socio-economic and democratic performance under crisis conditions, whereas vulnerable variants – president-parliamentary and presidentialized systems – are more susceptible to autocratization and institutional fragility. Accordingly, reform strategies should be tailored to the institutional type, prioritizing mechanisms that encourage executive cooperation, parliamentary oversight, and adaptive conflict resolution within hybrid regimes.

The study was conducted within the framework of the funding and service agreement (effective October 1, 2024) with the Center for Governance and Culture in Europe (GCE-HSG) at the University of St. Gallen, as part of the project “Prospects and Risks of Semi-Presidentialism in Conditions of Democratic Transition, Turbulence, and War: Quantitative and Statistical Comparative Analysis.”

Vitaliy S. Lytvyn contributed to conceptualization, research design, methodology, data analysis, and writing of the manuscript. Nazar O. Demchenko contributed to data curation and supported the development of the research framework. Volodymyr V. Babenko contributed to statistical analysis and correlation analysis. Ihor Yu. Osadchuk contributed to the analysis of selected cases. All authors contributed to the interpretation of results and approved the final manuscript.

Authors state no conflict of interest.

The data used in this study are available from publicly accessible sources. The processed data and materials supporting the findings of this study are available from the corresponding author upon reasonable request.