DOWNLOAD REPORT How can the United States deter two peer competitors? Russia’s illegal invasion of Ukraine has demonstrated Putin’s willingness to rely on nuclear threats to pursue regional ambitions. China’s expanding and increasingly diverse nuclear arsenal suggests that it, too, has ambitions that may rely on nuclear threats. U.S. political and military leaders need to determine the nation’s strategy to deter and, if necessary (and possible), defeat two nuclear peers simultaneously or in sequence. In doing so, leadership must also consider the implications of this strategy for nuclear force posture, nuclear modernization, extended deterrence and assurance, and arms control and disarmament strategy and commitments. To assist in addressing these challenges for U.S. strategy, the Project on Nuclear Issues (PONI) invited a group of experts to develop competing strategies for deterring two peer competitors through 2035. This publication was made possible by generous support from the Defense Threat Reduction Agency. This report is produced by the Center for Strategic and International Studies (CSIS), a private, tax-exempt institution focusing on international public policy issues. Its research is nonpartisan and nonproprietary. CSIS does not take specific policy positions. Accordingly, all views, positions, and conclusions expressed in this publication should be understood to be solely those of the author(s). © 2023 by the Center for Strategic and International Studies. All rights reserved.