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Research at cPASS targets questions in a variety of areas by applying innovative thinking and diverse methodologies (experiments, deductive modeling, statistical analysis, case studies, “big data”) to traditional security issues made more dynamic and difficult by increased complexity. We emphasize a team-based, multi-method approach to research that combines qualitative and quantitative perspectives; the strongest insights come from integrative approaches. Below is a sample of published research outputs from our ongoing projects. Adding an example.






  • Gartzke, Erik, Patrick Hulme, and Matthew Millard "Defeat is an Orphan" Submitted. 
  • Gartzke, Erik, Patrick Hulme, and Matthew Millard "Throwing in the Towel" (Typescript).
  • Gartzke, Erik, and Patrick Hulme. 2019. "The Tyranny of Distance: Assessing and Explaining the Apparent Decline in U.S. Military Performance." (Typescript).
  • Hulme, M. Patrick. 2019. "Critical Response to 'Legality and Legitimacy in American Military Intervention" (Submitted)
  • Hulme, M. Patrick, "A Not So Imperial Presidency?" (Typescript). 
  • Hulme, M. Patrick, "International Law with Chinese Characteristics" (Typescript).
  • Hulme, M. Patrick, "Will Trump start a war with Iran absent congressional approval?", Lawfare (Forthcoming).


  • Gartzke, Erik.  2018.  “Drafting Disputes:  Military Labor, Regime Type and Interstate Conflict.” Typescript.  

  • Gartzke, Erik, and Koji Kagotani. 2018.  “Trust in Tripwires:  Deployments, Costly Signaling and Extended General Deterrence.” Typescript.  

  • Gartzke, Erik, and Matthew Kroenig. 2018.  “Sleeping Giant or Paper Tiger?: Latent Potential, Conventional Capabilities and Interstate Conflict.” Typescript.

  • Gartzke, Erik, and Patrick Hulme.  2018.  “The Tyranny of Distance:  Assessing and Explaining the Apparent Decline in U.S. Military Performance.” Typescript.  

  • J Anders Gannon, Erik Gartzke, and Jon R. Lindsay, "After Deterrence: Explaining Conflict Short of War" under review
  • Kagotani, Koji, and Erik Gartzke.  2018.  “Gaining Credibility:  Alliances and U.S. Overseas Deployments” Typescript.

  • Lindsay, Jon, and Erik Gartzke.  2018.  Grand Strategy and Global Complexity: Security, Technology, and Prosperity in the 21st Century. Oxford:  Oxford University Press.

  • Lindsay, Jon R., and Erik Gartzke. 2018. “Coercion through Cyberspace: The Stability-Instability Paradox Revisited.” In Kelly M. Greenhill and Peter Krause, Coercion: The Power to Hurt in International Politics. New York: Oxford University Press, pp. 179–203.

  • Millard, M.C. (2018). "Rethinking the Kantian Peace: Evidence from a Liberal, Moderate, and Conservative Measure of Norm Diffusion." New Global Studies 12.3:325-341. 
  • Millard, M.C. and Porter, C. (2018). "Testing the Hard Case: Reactive Devaluation, Iran, and Nuclear Negotiations." Journal of Political Science 46. 








The University of California, San Diego, Center for Peace and Securities Studies (cPASS) leads two major projects sponsored by the Department of Defense's Minerva Initiative on cross-domain deterrence in collaboration with the University of California, Berkeley, Goldman School of Public Policy; the University of Toronto, Munk School of Global Affairs; the University of Maryland, Center for International Development and Conflict Management; the Lawrence Livermore National Laboratory; and the Los Alamos National Laboratory. cPASS is also currently engaged in a number of ongoing projects on military platforms, military posture, and military automation. 

Deterring Complex Threats: The Effects of Asymmetry, Interdependence, and Multi-polarity on International Strategy

Principal Investigator: Dr. Erik Gartzke

Co-PI: Dr. Jon R. Lindsay


  • Department of Defense

  • Minerva Initiative

  • Office of Naval Research

Award Number: N00014-14-0071

Abstract: Deterrence as a strategy and doctrine was convincingly and effectively deployed by the United States during the Cold War. Today, however, states face a widening range of destabilizing threats, in particular to space, cyberspace, financial, and other critical infrastructure. The interconnectedness of the contemporary world creates many new opportunities for state or non-state adversaries to seek asymmetric advantages (i.e., low-cost actions which undermine high-cost sources of power) against advanced industrial countries, including the United States. Technological and political complexity generates tremendous uncertainty, undermining in one stroke both the simple logic of the basic deterrence frameworks applied in the previous era and also the credibility of such efforts. “Cross domain deterrence”

(CDD) seeks to counter threats in one arena (such as space or cyber warfare) by relying on different types of capabilities (such as sea power or nuclear weapons, or even non-military tools such as access to markets or normative regimes) where deterrence may be more effective. The increasing complexity of

CDD poses both opportunities and challenges that necessitate, and will benefit from, a major evolution in thinking (and practice) about how deterrence operates.

The University of California Center for Peace and security (cPASS), in collaboration with the Lawrence Livermore (LLNL) and Los Alamos National Laboratories (LANL), aims to develop analytical clarity concerning the effects of increasing technological and political complexity on the logic of CDD. We combat the complexity of CDD by breaking the concept into three complementary characteristics of the global political system: asymmetryinterdependence, and multipolarity. These interrelated concepts are strongly affected but not uniquely determined by emerging technologies. They build on one another in a modular yet cumulative process which will enable us to systematically explore key questions such as: How does asymmetric access to nuclear weapons, counterspace operations, and cyberspace capabilities shape threats and the use of force? How does politicaleconomic and technological interdependence affect strategic calculations and a willingness to fight or compromise? How does the proliferation of diverse types of weapons to a growing number of actors shape the nature of deterrence or alter its scope? Answers to these questions promise to advance the social science of national security and inform policy for tackling emerging cross-domain threats.

Defense Education and Civilian University Research (DECUR)

DECUR Project Title: Economic Interdependence and National Security in the 21st Century

An unprecedented level of economic interdependence complicates development of any U.S. strategy for competition with rivals like China or Russia. This heightened economic interdependence between allies and competitors alike both shapes the costs of military conflict and makes available new tools of economic statecraft and coercion. How can the United States and its allies strategically manage their common commercial ties to avoid vulnerabilities and achieve leverage against strategic competitors? How can the United States coordinate use of economic power with its strategic partners to achieve key interests while minimizing the likelihood of armed conflict, or at the least, minimizing the likelihood of American casualties? More broadly, to what extent and under what conditions can tools of economic statecraft supplement or even supplant military power and reduce lethal risk to U.S. military personnel?

Our research aims to answer these questions by creating new insights focused on three areas: (1) exploring the ways in which asymmetric interdependence in investments and financial flows shape states’ power and vulnerability with respect to economic coercion; (2) defining the ways interdependence complicates cooperation and coordination among allies; and (3) creating a country-specific decision-guidance framework to help defense policy makers evaluate economic statecraft tools with respect to China and Russia.


PME Principle Investigator:                                            
David Sacko, Professor, United States Air Force Academy

Civilian Principle Investigator: 
Erik Gartzke, Professor, University of California at San Diego

Jack Zhang, Assistant Professor, University of Kansas
Ben Graham, Associate Professor, University of Southern California
Neil Narang, Associate Professor, University of California at Santa Barbara
Paul Bolt, Department Head, Professor of Political Science, United States Air Force Academy


Learn more about this project here.

An Empirical Approach to Cross-Domain Deterrence

Principal Investigator: Dr. Erik Gartzke

Co-PI: Dr. Jon R. Lindsay


  • Department of Defense

  • Minerva Initiative

  • Office of Naval Research

Award Number: N00014-15-1-2792

Abstract: The rise of new technological capabilities and concerns involving space and cyberspace create a pressing need for a better understanding of how conflict and cooperation are conducted across different domains, and where crossing domains creates special challenges and opportunities for deterrence, compellence and other forms of influence. We have now encountered a number of nuanced cases of complex deterrence involving many means, so many that a purely qualitative approach to empirical analysis is no longer the only approach to historical data.

 We have identified existing datasets that we are enhancing to incorporate information about capabilities and interaction in and across various domains.  Conducting innovative tests of cross-domain crises and conflict also necessitates the development of new variables to capture the increase in complexity associated with technological innovation. Finally, we have a new measure of how uncertainty about a state’s capabilities varies across domains. These data promise new insights into the way cross-domain deterrence operates in the real world.

Cross-Domain Deterrence Edited Volume

Now Available! Get a copy here.

Military Platforms and Domains

Attributes of military capabilities affect the kinds of outcomes societies can seek, and obtain, in world affairs. Characteristics of weapons that make them more effective on the battlefield may also weaken their ability to convey intent. Navies, for example, are highly mobile and effective at concentrating firepower. Naval surface platforms wield considerable influence by “showing the flag,” while other platforms, such as submarines, are characterized by stealth rather than visibility. Work by cPASS explores the ways in which military power shapes the kind of outcomes nations can expect from given force structure decisions.  Analyzing variation in the domains and platforms used during and prior to warfare over the past two centuries can shed valuable insight regarding what domains and platforms succeed in achieving national objectives and during what circumstance. This project is unique in that it explores platform and domain capabilities by all countries that have been involved in international crises.

Effects of Military Automation

A variety of innovative technologies are changing the nature of warfare. These technologies have contrasting effects, depending on how they interact with the political processes of states. Technologies that supplant human labor in battle—such as UAVs (drones) and ground combat robots—lower military labor costs and limit political risks associated with friendly casualties. The tendency should thus be for military automation to increase the scope of threats or uses of force by the most advanced economies, geographically and in terms of the issues in dispute. These and other insights have been developed in a theoretical paper and in a quantitative study of U.S. drone strikes in Pakistan.

Technologies that do not replace humans on the battlefield, but which instead make defense more effective should have the opposite effect, reducing aggression by other states or actors against the technological power. In two separate studies—one on the effects of nuclear weapons platform diversification on deterrence success and a second addressing the impact of military surveillance satellites—these technologies enhance deterrence or defense, making aggression less effective and lowering the costs/risks associated with national security. These capabilities also substitute to some extent for a forward force posture, reducing the need for costly foreign basing.

Effects of Military Posture

The United States faces key questions of foreign policy efficacy and tradeoffs between its national priorities in a period of relative decline. How (and where) can the United States deploy its military capabilities to best achieve security and maintain influence, while minimizing costs? A series of cPASS studies explore these questions. First, we examine the classical conception of military deployments as “tripwires,” showing that a more accurate empirical description involves signals of U.S. priorities and resolve. It is not how many forces are deployed to an ally that matters for general deterrence success, but what proportion of available U.S. forces are deployed in a given country. The finding also suggests that relative U.S. decline need not undermine global stability, provided that America telegraphs its priorities, implying a policy of restraint combined with a limited forward force posture.

The question of whether forward force postures stabilize or inflame is examined in the next study. Work by cPASS finds that the proportion of U.S. forces deployed to an ally significantly correlates with reduced challenges by an ally’s rivals. Finally, we critically examine the effect of presence versus offshore balancing. It would be appealing to be able to protect security partners from abroad. However, we find that forces near, but not on the territory of an ally actually undermine stability. It turns out that “being there” makes a difference for deterrence success.

Effects of the Volunteer Force

Controversy in the aftermath of U.S. involvement in the Vietnam War led to a national reassessment of the basis for recruitment of military labor. Beginning in the 1970s, a series of countries repealed conscription in favor of a volunteer force. Critics have argued that a volunteer force provides the executive with greater discretion in the use military power. Nevertheless, previous systematic studies of this relationship identified the opposite relationship; volunteers appeared to make countries less warlike, not more. A new analysis of military recruitment reconciles this apparent contradiction by noting that veto players serve contrasting functions in democracies and autocracies. In democracies, voluntary service makes the use of force more likely, while conscription achieves a similar effect in autocratic states. The effect is strong and robust to alternative explanations. Future work will extend the analysis to additional aspects of civil-military affairs in free societies.

Book Project: The Futility of War

Economic development and the globalization of commercial ties have fundamentally changed the nature of international affairs. In places, this has meant a cessation of the motives for war. More broadly, modernity has shifted the ends to which nations apply military power. Sophisticated, powerful states expend an increasing effort on shaping the terms under which states interact, while showing little interest in exercising expensive military power to expropriate relatively cheap assets such as territory or natural resources. This shift away from using military force to appropriate tangible goods and toward coercing compliance with preferred international policies will be reinforced by new technological change. I lay out a theory of conflict and peace tied to modernity, demonstrate implications using statistical and other data-driven approaches and then leverage the theory to help explain likely future developments tied to military automation and cyberwar.


cPASS also manages an array of internal research labs and institutional divisions dedicated to the intersection of questions from political science, cybersecurity, and interdisciplinary methods. 

Machine-Learning for Social Science Lab (MSSL)

The Machine Learning for Social Science Lab (MSSL) is dedicated specifically to the intersection of questions from the social sciences and methods from computer science and mathematics. MSSL will serve as a long term institutional home to data collection efforts and methodological tools that otherwise exist as informal, scattered, and temporary collaborations between individual scholars.

Learn more about the lab here.

Cyber Escalation Lab (CEL)

This lab will serve as the institutional home for a critical mass of researchers capable of analyzing and contributing to an analytical social science of cyber conflict. CEL will develop a keystone data project to form the empirical basis for analysis and debate on the subject. Together, these strategies will allow young scholars at the intersection of cyber and international relations to test theories using this data and develop their CV and to build out their networks to succeed in the field.

To join our community, fill out this form for (rare!) email updates and to get on the cyber escalation primer.

Learn more about the lab here.