Why do armies sometimes surrender to the enemy and sometimes fight to the bitter end? Existing research has highlighted the importance of battlefield resolve for the onset, conduct, and outcome of war, but has left these life-and-death decisions mostly unexplained. We know little about why battle-level surrender occurs, and why it stops. In this paper, we argue that surrender emerges from a collective-action problem: success in battle requires that soldiers choose to fight as a unit rather than flee, but individual decisions to fight depend on whether soldiers expect their comrades to do the same. Surrender becomes contagious across battles because soldiers take cues from what other soldiers did when they were in a similar position. Where no recent precedent exists, mass surrender is unlikely. We find empirical support for this claim using a new data set of conventional battles in all interstate wars from 1939 to 2011. These findings advance our understanding of battlefield resolve, with broader implications for the design of political-military institutions and decisions to initiate, continue, and terminate war.

What explains differential rates of ethnic violence in postcolonial Africa? I argue that ethnic groups organized as a precolonial state (PCS) exacerbated interethnic tensions in their postcolonial country. Insecure leaders in these countries traded off between inclusive coalitions that risked insider coups and excluding other ethnic groups at the possible expense of outsider rebellions. My main hypotheses posit that PCS groups should associate with coups because their historically rooted advantages often enabled accessing power at the center, whereas other ethnic groups in their countries—given strategic incentives for ethnopolitical exclusion—should fight civil wars more frequently than ethnic groups in countries without a PCS group. Analyzing originally compiled data on precolonial African states provides statistical evidence for these implications about civil wars and coups between independence and 2013 across various model specifications. Strikingly, through 1989, thirty of thirty-two ethnic group-level major civil war onsets occurred in countries with a PCS group.

What type of trade agreement is the public willing to accept? Instead of focusing on individual concerns about market access and trade barriers, we argue that specific treaty design and, in particular, the characteristics of the dispute settlement mechanism, play a critical role in shaping public support for trade agreements. To examine this theoretical expectation, we conduct a conjoint experiment that varies diverse treaty-design elements and estimate preferences over multiple dimensions of the Transatlantic Trade and Investment Partnership (TTIP) based on a nationally representative sample in Germany. We find that compared to other alternatives, private arbitration, known as investor-state dispute settlement (ISDS), generates strong opposition to the trade agreement. As the single most important factor, this effect of dispute settlement characteristic is strikingly large and consistent across individuals’ key attributes, including skill levels, information, and national sentiment, among others.

What are the effects of international intervention on the rule of law after civil war? Rule of law requires not only that state authorities abide by legal limits on their power, but also that citizens rely on state laws and institutions to adjudicate disputes. Using an original survey and list experiment in Liberia, I show that exposure to the UN Mission in Liberia (UNMIL) increased citizens’ reliance on state over nonstate authorities to resolve the most serious incidents of crime and violence, and increased nonstate authorities’ reliance on legal over illegal mechanisms of dispute resolution. I use multiple identification strategies to support a causal interpretation of these results, including an instrumental variables strategy that leverages plausibly exogenous variation in the distribution of UNMIL personnel induced by the killing of seven peacekeepers in neighboring Côte d'Ivoire. My results are still detectable two years later, even in communities that report no further exposure to peacekeepers. I also find that exposure to UNMIL did not mitigate and may in fact have exacerbated citizens’ perceptions of state corruption and bias in the short term, but that these apparently adverse effects dissipated over time. I conclude by discussing implications of these complex but overall beneficial effects.

Recent international relations scholarship has argued that political elites constrain the use of military force by democracies. Despite the persuasiveness of this research, scholars have largely ignored elite dynamics’ ability to constrain the initiation of covert operations. This omission is consequential because scholars of US foreign policy often assume that covert operations serve as a substitute for the overt use of force; secrecy allows leaders to limit information to congressional elites and thus weaken their oversight capabilities. Do elite political dynamics constrain presidents’ ability to act secretly or do they affect the overt use of force only? I argue that elite political constraints—particularly opposition from Congress—extend to the president's ability to initiate covert operations. By examining the trade-off between US military force and CIA-initiated covert operations during the Cold War, I find the likelihood that covert operations are initiated decreases significantly during periods of divided government and that there is no distinguishable trade-off between covert operations and overt military force. The results suggest that constraints on covert operations became more uniform across unified and divided government following congressional oversight reforms in 1975 that reduced the information asymmetry between the majority and minority party. These findings have important ramifications for the nascent literature on back-door bargaining and covert signalling. Because democratic leaders frequently face domestic political costs even when acting in secret, covert operations should allow leaders to credibly convey their resolve.

Indiscriminate violence against civilians has long been viewed as a catalyst for new rounds of violence in civil wars. Can humanitarian assistance reduce violence after civilians have been harmed? Crossnational studies are pessimistic, drawing a connection between humanitarian aid and increased civil war violence, lethality, and duration. To date, however, we have few subnational studies of wartime aid and subsequent violence. To examine this relationship, I draw on the Afghan Civilian Assistance Program (ACAP II), a USAID-funded initiative that investigated 1,061 civilian casualty incidents (2011–13). Aid was assigned as if randomly to about half (55.8%) of these incidents, facilitating counterfactual estimation of how assistance affected Taliban attacks against the International Security Assistance Force, Afghan forces, and civilians. Challenging prior studies, I find that ACAP was associated with an average 23 percent reduction in attacks against ISAF, but not Afghan forces or civilians, at the village level for up to two years after the initial incident.

Bureaucracies with field operations that cannot be easily supervised and monitored by managers are caught between two sources of dysfunction that may harm performance. The first source of dysfunction is straightforward: field workers can use operating slack and asymmetric information to their own advantage, thwarting an organization's objectives. The second source of dysfunction is often overlooked: attempts to limit workers’ autonomy may have deleterious effects, curbing agents’ ability to respond efficaciously to the environment. I find that the parliaments and executive boards to whom International Development Organizations (IDOs) are accountable differentially constrain IDO organizational autonomy, which in turn affects management's control of field agents. Tight management control of field agents has negative effects, particularly in more unpredictable environments. Attempts by politicians to constrain organizations in an effort to improve performance can sometimes be self-undermining, having net effects opposite those intended.

While extensive research shows that policies and institutions spread across states through processes of diffusion, we know little about diffusion among international organizations (IOs). We develop a novel approach for the study of diffusion among IOs. This approach consists of three components: a theoretical focus on connectivity among IOs as pathways for diffusion; a conceptual differentiation between alternative types of convergence effects; and a methodological strategy combining dyadic and spatial analysis of diffusion. We illustrate the usefulness of this approach through an empirical case: the diffusion of participatory governance arrangements among IOs from 1970 to 2010. The analysis shows that connectivity among IOs contributes to convergence, which typically is manifested through imitation of very specific institutional models. The article's findings have implications both for the study of IOs and for the general study of diffusion.

The United States' 1890–91 decision to begin building a battleship fleet, an important point in its development as a world power, can illuminate the domestic sources of foreign policy ambition. An analysis of roll-call votes in the House of Representatives indicates that socioeconomic divisions arising from industrialization strongly influenced support and opposition to the battleship fleet. This relationship worked mainly through trade policy interests: members of Congress from import-competing states tended to support the effort, while those from export-oriented states tended to oppose it. The patriotic symbolism of battleships at a time of labor unrest also helped motivate support for the program, though evidence of this pattern is less conclusive. Although party affiliation was crucial, it was also partly a function of economic structure, which shaped the two parties’ electoral fortunes. The impact of trade interests during this period is a mirror image of what previous research has found concerning the post-World War II era, when export-oriented interests tended to support American global activism and import-competing interests to oppose it. The reason for the difference is the Republican Party's commitment to trade protection, which strongly influenced both the goals of the policy and the identity of its supporters.

In the past few years the Western world has witnessed a rise in the popularity of right-wing political discourse promoting nationalistic and exclusionary world views. While in many countries such rhetoric has surfaced in mainstream politics only recently, in Israel, right-wing ideology has been popular for almost two decades. Explanations for this phenomenon focus on Israeli citizens’ attitudinal change in the face of exposure to terrorism but largely do not account for why such ideas remain popular over the long term, even after violence subsides. In this study I examine whether the long-lasting prominence of right-wing nationalistic politics in Israel is linked to the perpetuation of right-wing ideology in popular media. Analyzing the content of more than 70,000 published books, I find that content related to the political right has increased in Israeli books after periods of terrorism, a change that has become more pronounced over the years.

We present a two-stage approach to civil conflict analysis. Unlike conventional approaches that focus only on armed conflict and treat all other cases as “at peace,” we first distinguish cases with and without contested incompatibilities (Stage 1) and then whether or not contested incompatibilities escalate to armed conflict (Stage 2). This allows us to analyze factors that relate to conflict origination (onset of incompatibilities) and factors that predict conflict militarization (onset of armed violence). Using new data on incompatibilities and armed conflict, we replicate and extend three prior studies of violent civil conflict, reformulated as a two-stage process, considering different estimation procedures and potential selection problems. We find that the group-based horizontal political inequalities highlighted in research on violent civil conflict clearly relate to conflict origination but have no clear association with militarization, whereas other features emphasized as shaping the risk of civil war, such as refugee flows and soft state power, predict militarization but not incompatibilities. A two-stage approach to conflict analysis can help advance theories of civil conflict, assess alternative mechanisms through which explanatory variables are thought to influence conflict, and guide new data-collection efforts.

Gender stereotypes—stylized expectations of individuals’ traits and capabilities based on their gender—may affect the behavior of diplomats and the processes of international negotiations. In a survey experiment in the Council of the European Union, we find that female representatives behaving stereotypically weak and vulnerable may trigger a chivalry reaction among male representatives, increasing the likelihood that the men will agree to support a bargaining proposal from the women. The effect is conditional on the negotiators’ cultural background—the chivalry reaction is displayed mainly by diplomats from countries with relatively low levels of gender equality. Our study contributes to the research on nonstandard behavior in international relations, and in particular the expression and reception of emotions in diplomacy. We argue that gender stereotypes may have a moderating impact on decision making based on such intuitive cognitive processes. We also add to the broader negotiation literature, both by showing the pervasiveness of gender stereotyping, and by testing at the elite level the generalizability of claims regarding gender effects derived from laboratory experiments. Overall, our findings demonstrate the importance of bringing gender into the study of international negotiations, where it has been largely and surprisingly ignored.