My primary research interest is in the causes of war and peace, and in particular in how countries that are at war
transition back to peace. In addition, I have interests in systemic theorizing about war and in the relationship
between ideational variables like reputation or ideology and international conflict.

My book, entitled Logics of War: Explanations for Limited and Unlimited Conflicts, examines the determinants of
interstate war destructiveness. Put simply, I ask what separates the many limited wars, in which fighting ends quickly
or is never particularly intense, from the few in which high-intensity fighting continues for years. Building on the
bargaining model of war, I examine three mechanisms that all can lead to costly conflict: informational asymmetries that
lead to overoptimism, principal-agent problems in domestic politics, and commitment problems. I argue that the first two
mechanisms are logically limited, either because fighting forces the participants to recognize their initial miscalculations
or because other domestic political actors constrain leaders who would prefer to fight wars to serve their own interests.
Unusually destructive wars thus are disproportionately driven by commitment problems. In addition to the well-known
shifting power logic of commitment problems, in which declining powers launch preventive wars to forestall the effects
of decline, I argue that in rare but important cases we observe what I refer to as a dispositional commitment problem,
in which the target of a preventive war concludes that its opponent is by nature committed to aggression, and hence that
sustained peace will require the remaking of the opposing regime. This conclusion leads logically to the categorical
refusal to negotiate and hence to wars to the death. I derive testable hypotheses from these arguments that I test both
statistically, using both standard datasets and novel data, and qualitatively, in nine case studies of both well-known
and relatively obscure conflicts over the past two centuries. The book was published by Cornell University Press in 2013,
and is available for purchase here. Supplemental appendices and replication data are available at my Dataverse site here.

In my second project, I am examining the regional logic of war, focusing in particular on the emergence, maintenance,
and dissolution of endemic regional conflict in places like 19th-century South America, interwar Eastern Europe, and
contemporary Central and Eastern Africa. I identify mechanisms whereby conflict between two actors (A and B) can
increase the probability that we observe war break out between two completely separate actors (C and D), thereby allowing
endemic regional conflict to emerge and persist, as well as potential avenues by which regions of endemic conflict might
ultimately transition to peace. I test arguments both through general statistical tests over the entire post-Napoleonic
international system as well as both quantitative and qualitative analysis of historical regions that experienced this
sort of endemic violence.

I also have a number of published and working papers that relate to these themes of war termination and the systemic logic
of violence. In three papers co-authored with Erik Gartzke, we critique existing systemic variants of the democratic
peace and argue that the propensity for intra-regime conflict and cooperation should be driven by the system-level prevalence
of a particular regime type (implying that the effects of the democratic peace will weaken as democracy becomes the norm)
and that there is clearer logic and evidence for a system-level developmental peace. In other work, I argue that while
a hearts and minds strategy may prove most effective at defeating an established insurgency, willingness and ability to
resort to relatively brutal tactics historically has been more effective at preventing the initial emergence of insurgent
resistance. Other ongoing work examines the determinants of defection from wartime coalitions, the significance of past
action (reputation) in international politics, and the implications of political ideology for conflict.

I have also been involved in two major data collection efforts: the War Initiation and Termination (WIT) project organized
by Tanisha Fazal and Page Fortna and also involving Jessica Stanton, and an ongoing effort to collect estimates of monthly
battle deaths for participants in the Correlates of War interstate wars.

Published and forthcoming work:

Learning from the Battlefield: Information, Domestic Politics, and Interstate War Termination, forthcoming, International Organization.

Revisiting Reputation: How Past Actions Matter in International Politics (with Keren Yarhi-Milo), forthcoming, International Organization.

Victory without Peace: Conquest, Insurgency, and War Termination.

Permanent Friends? Dynamic Difference and the Democratic Peace (with Erik Gartzke)

Fading Friendships: Alliances, Affinities, and the Activation of International Identities (with Erik Gartzke)

Under Construction: Development, Democracy, and Difference as Determinants of the Systemic Liberal Peace (with Erik Gartzke)

The Limits to Partition (correspondence, with Michael C. Horowitz)

Working papers and papers under review:

Exiting the Coalition: When Do States Abandon Allies Partners During War? R&R, International Studies Quarterly

Identifying and Testing Logics of Regional War Diffusion

Shifting Power and Regional Conflict: Explaining Persistent Regional War

Ideology, Ideologues, and War