Cross-domain deterrence: strategy in an era of complexity

The complexity of the 21st century threat landscape contrasts significantly with the bilateral nuclear bargaining context envisioned by classical deterrence theory. Nuclear & conventional arsenals continue to develop alongside antisatellite programs, autonomous robotics or drones, cyber operations, biotechnology, & other innovations barely imagined in the early nuclear age. The concept of cross-domain deterrence emerged near the end of the George W. Bush administration as policymakers & commanders confronted emerging threats to vital American military systems in space & cyberspace. The Pentagon now recognizes five operational environments or so-called domains (land, sea, air, space, & cyberspace), & cross-domain deterrence poses serious problems in practice. This text steps back to assess the theoretical relevance of cross-domain deterrence for the field of international relations.

Deterrence theory, which emerged during the Cold War, explains how states can use nuclear threats to prevent nuclear war. Today, however, the threat landscape is significantly more complex. Alongside ever-more sophisticated nuclear weapons arsenals, contemporary threats include cyberwarfare, anti-satellite weapons, robotic drones, and advanced conventional weapons. To deal with the new threat environment, the Pentagon identified five operational domains: land, sea, air, space, and cyberspace. The resulting model is an integrated, flexible regime that is able to deter threats across domains. In this volume, a leading cast of scholars and national security practitioners explore the logic and application of cross-domain deterrence in theory and practice.