Alexandre Debs

Regime Type, the Fate of Leaders, and War

We propose and test a formal model of war and domestic politics, building on recent evidence on the relationship between regime type, the effect of war on the probability of losing office, and the consequences of losing office. The less the outcome of international interaction affects a leaders tenure and the less punitive are the consequences of losing office, the more a leader is willing to make concessions to strike a peaceful bargain. We demonstrate that our theory successfully predicts war involvement among nondemocratic regime types. Moreover, our theory offers an intuitive explanation for the democratic peace. Compared to nondemocratic leaders, the tenure of democratic leaders depends relatively little on the war outcome, and democratic leaders fare relatively well after losing office. Thus, democratic leaders should be more willing and able to avoid war, especially with other democrats.

Known Unknowns: Power Shifts, Uncertainty, and War

Large and rapid power shifts resulting from exogenous economic growth are considered sufficient to cause preventive wars. Yet most large and rapid shifts result from endogenous military investments. We show that when the investment decision is perfectly transparent, peace prevails. Large and rapid power shifts are deterred through the threat of a preventive war. When investments remain undetected, however, states may be tempted to introduce power shifts as a fait accompli. Knowing this, their adversaries may strike preventively even without conclusive evidence of militarization. In fact, the more effective preventive wars are, the more likely they will be launched against states that are not militarizing. Our argument emphasizes the role of imperfect information as a cause of war. It also explains why powerful states may attack weaker targets even with ambiguous evidence of their militarization. We illustrate our theory through an account of the 2003 US-led invasion of Iraq.

Inequality under Democracy: Explaining the Left Decade in Latin America

Inequality is generally thought to affect the electoral fortunes of the left, yet the theory and evidence on the question are unclear. This is the case even in Latin America, a region marked by enormous inequalities and by the stunning return of the left over the last decade. We address this shortcoming. Our game-theoretic model reveals that the probability that the left candidate is elected follows an inverted U-shaped relationship. At low levels of inequality, the rich do not bribe any voters and poor voters are increasingly likely to vote for the left candidate based on redistributive concerns. At high levels of inequality, the rich want to avoid redistribution and bribe poor voters, causing the left candidate to be elected with decreasing probability. We find support for our hypothesis, using 110 elections in 18 Latin American countries from 1978 to 2008.

Circumstances, Domestic Audiences, and Reputational Incentives in International Crisis Bargaining

We present a new theory of interstate crisis bargaining. A country’s resolve is a function of intrinsic qualities of the government and external circumstances, both of which are unknown by the domestic electorate and the foreign country. When domestic political debate reveals that circumstances favor the use of force, the government can extract better terms than if circumstances are revealed to be unfavorable. The revelation of circumstances, however, exacerbates reputational incentives. Because governments can no longer hide behind unknown circumstances, voters can better discern the government’s type from its actions, strengthening the incentives to appear resolved. The model bridges the gap between audience costs and its critiques, showing how domestic audiences punish leaders for inappropriate policies rather than empty threats. At the same time, it highlights how the prospects for peace are worse if uncertainty about the circumstances is removed, suggesting that greater transparency does not always promote peaceful outcomes.

Cascading Chaos in Nuclear Northeast Asia

The election of Donald J. Trump challenged some long-held core tenets of U.S. foreign policy. For decades, U.S. administrations have valued the nonproliferation of nuclear weapons among their most important foreign policy goals. At the same time, Washington has expanded its global influence by extending robust security guarantees to numerous countries around the globe. Finally, the United States has established strategic stability vis-à-vis its nuclear adversaries by relying heavily on the doctrine of deterrence. These three policies, as the analysis below will show, are deeply connected. Security assurances to allies, combined with a focus on deterring—rather than rolling back—adversary regimes, have long been among the most effective tools in Washington’s nuclear nonproliferation toolkit. The limited spread of nuclear weapons that resulted from these policies, in turn, has made it possible for the United States to expand its global influence and achieve its broader strategic goals at relatively low cost, avoiding major wars against nuclear adversaries and exercising a great deal of influence over its protégés. Intent on breaking with past practice, the Trump administration has questioned the wisdom of U.S. security commitments to allies around the world, all the while escalating its rhetoric with nuclear adversaries. Both these moves undermine longstanding policies aimed at avoiding nuclear proliferation toward U.S. allies. If fully implemented, a U.S. strategy that would decrease the level of U.S. commitment to the security of its allies while increasing the aggressiveness of U.S. goals vis-à-vis