Research

Publications

• Sert, Hilal and Anthony J. DeMattee. Forthcoming. “The Role of Militarized Interstate Disputes in Presidential Term Limit Evasions: From Crisis to Consolidation.” Journal of Peace Research. DOI: 10.1093/jopres/xjag078.

• Abstract

  Militarized interstate disputes (MIDs) have well-documented effects on public opinion and executive authority, yet their implications for domestic institutional change remain underexplored. We argue that interstate conflict reshapes leaders' incentives in ways that facilitate presidential term limit evasion (TLE). Early-stage disputes can generate rally effects that expand executive discretion and reduce resistance to constitutional change. As conflicts persist, public fatigue and uncertainty about leadership turnover may increase the appeal of continuity, altering both the feasibility and the mode of institutional reform. We argue that prolonged hostile MIDs make referendums, where executives can mobilize conflict-conditioned public support, more attractive than legislative or judicial channels, which become increasingly risk-averse under prolonged conflict. Using an extended dataset on executive term limits in Sub-Saharan Africa and Latin America from 1989 to 2023, we show that interstate conflict is most closely associated with referendum-based TLE attempts, and that prolonged hostile disputes substantially raise the likelihood of successful referendum-led evasions. These findings contribute to research on executive aggrandizement, institutional change, and the domestic consequences of international conflict by identifying a pathway through which interstate insecurity can shape constitutional politics. The article shows that conflict does not merely affect public opinion or leader survival; it can also influence how incumbents seek to revise the rules that govern political succession.

Papers Submitted for Review

• Sert, Hilal and Burak Kazim Yilmaz. “Signals of Vulnerability: Electoral Defeat and Coordinated Elite Defection in Turkey”.

• Abstract

  How do electoral defeats affect elite cohesion in competitive authoritarian regimes? We argue that electoral defeats can undermine ruling-party cohesion by providing a public signal of incumbent vulnerability. Dissatisfied elites may recognize weaknesses in the regime yet hesitate to defect when exit is costly and they are uncertain whether others will follow. A publicly observed electoral defeat can reduce this uncertainty and provide a focal point for coordinated exit. We examine this argument using an original dataset of 2,529 parliamentary candidates from Turkey's ruling AKP. Following the opposition's decisive victory in the June 2019 rerun of the Istanbul mayoral election, the incidence of elite defection increased sharply, with the increase concentrated in the months immediately following the election. The increase is concentrated in coordinated rather than independent exits: the incidence of coordinated defection rises sharply after the rerun, whereas independent defection does not increase. These findings provide evidence that elections can weaken competitive authoritarian regimes not only through electoral turnover, but also by revealing incumbent vulnerability and facilitating coordination among ruling-party elites.

• Batista, Ian Rebouças, Hilal Sert, Anthony J. DeMattee and David Carroll. “The Presidential Term Limits Evasion Global Dataset and the Consequences to Electoral Integrity.”.

• Abstract

  Presidential term-limit evasion (TLE) is a significant driver of democratic backsliding and potentially undermines electoral integrity, yet this relationship warrants further causal investigation. This note presents the Presidential Term Limits Evasion Global Dataset, covering 676 presidential terms across 97 countries (1989–2023), as a new resource for studying this power-grabbing maneuver in democracies and its lasting consequences. The dataset covers original data collection for the modes of the TLE, Court Ruling, Legislative Amendment, or Popular Referendum, totaling 52 TLE cases. It also incorporates previous TLE coding efforts, becoming a comprehensive reference dataset on presidential TLE. To demonstrate the potential of the dataset, we apply a difference-in-differences approach to examine the relationship between different modes of TLE (Court, Legislative, Referendum) and several key electoral integrity measures, including electoral quality perception, Electoral Management Body autonomy, and election-day irregularities. Our findings confirm prior studies that court rulings TLEs are the most detrimental to electoral integrity. These findings strengthen causal claims about the impacts of TLE on electoral integrity and provide critical new insights into the institutional pathways through which TLE erodes democratic institutions and norms.

Books

• Sert, Hilal. “Tit for Tat? Reciprocity, Retaliation, and Escalation After Foreign Rebel Support.” (In Progress)

Working Papers

• Sert, Hilal. “Rebels or Rockets? Retaliation Strategies Against Rebel Sponsorship.” (draft available at request)

• Abstract

  Why does foreign rebel sponsorship generate retaliation but rarely immediate interstate war? This article develops a theory of retaliatory repertoires in response to foreign support for rebel groups. I argue that targeted states often respond through within-domain reciprocity: supporting rebels against the original sponsor allows them to impose costs, signal resolve, and preserve strategic flexibility while limiting the risks of direct military escalation. Direct force can also communicate resolve, but more severe uses of force carry higher escalation costs. Using global data on foreign rebel support and militarized interstate disputes, I show that prior rebel-support targeting increases the likelihood of subsequent responses and that these responses are concentrated in less escalatory instruments. Targeted states are most likely to respond with rebel support, less likely to use proportionate force, and least likely to escalate to war-level force. Conditional analyses show that rebel-group availability is the strongest predictor of response, while shared ethnic ties and relative economic capacity shape more selective parts of the retaliatory repertoire. Responder trade dependence, by contrast, provides limited evidence of a systematic constraint on retaliation. The article contributes to research on proxy warfare, coercive signaling, and conflict escalation by showing how states respond across domains without necessarily crossing the threshold into interstate war.

• Sert, Hilal and Burak Kazim Yilmaz. “When Repression Divides: Peace Process and Opposition Fragmentation in Turkey.” (draft available at request)

• Abstract

  This paper examines how Turkish politicians framed repression against the main opposition during a period also shaped by a peace process between the government and Kurdish insurgents. We argue that repression is not only a coercive act, but also a communication and agenda-setting problem: its political costs depend partly on whether opposition actors converge around a shared interpretation of the crisis. Using LLM-assisted coding of 216,628 social media posts by 590 Turkish politicians from March 1 to July 30, 2026, the analysis finds that opposition discourse was fragmented. Politicians most directly affected by the crackdown were especially likely to foreground repression against the main opposition, while pro-Kurdish opposition politicians were more likely to emphasize repression not centered on the main opposition party and the peace process; nationalist opposition politicians were less active on repression frames. Government-aligned politicians, by contrast, were more likely to emphasize foreign policy and security. The broader lesson is that authoritarian governments can exploit politically charged issues to divide opposition blocs and lower the political costs of repression. Peace processes, for example, can become wedge issues that weaken opposition solidarity.
• Sert, Hilal and Burak Kazim Yilmaz. “Public Support for Retaliation Against Rebel Sponsors.” (work in progress)

Other Publications

• Hilal Sert, Burak Kazim Yilmaz, and Anthony J. DeMattee. 2026. “Repression Under the Cover of Peace: The Peace-Democracy Wedge in Turkish Politics.” The Democracy Program, The Carter Center. Atlanta, GA.

Datasets

• Carlin, Ryan E., Jonathan Hartlyn, Timothy Hellwig, Gregory J. Love, Cecilia Martinez-Gallardo, Matthew M. Singer, Juan S. Gomez- Cruces, and Hilal Sert. 2023. Executive Approval Database 3.0. OSF. DOI: 10.17605/OSF.IO/84MJX. Available for download at Executive Approval Project.