War Powers and the Return of Major Power Conflict

University of Chicago Legal Forum Volume 2024 Article 1 2025 War Powers and the Return of Major Power Conflict Scott R. Anderson Follow this and additional works at: https://chicagounbound.uchicago.edu/uclf Part of the Law Commons Recommended Citation Anderson, Scott R. (2025) "War Powers and the Return of Major Power Conflict," University of Chicago Legal Forum: Vol. 2024, Article 1. Available at: https://chicagounbound.uchicago.edu/uclf/vol2024/iss1/1 This Article is brought to you for free and open access by Chicago Unbound. It has been accepted for inclusion in University of Chicago Legal Forum by an authorized editor of Chicago Unbound. For more information, please contact . War Powers and the Return of Major Power Conflict Scott R. Andersont ABSTRACT The United States is, by many accounts, facing a renewed risk of majorpower conflict. This Article considers what the reemergence of this risk may mean for the executive branch's operationalunderstandingof constitutionalwar powers, specifically as they relate to the use of military force. After outlining the relationship between U.S. strategicconcerns and executive branchlegal interpretationsand reviewing the most recent historicalparallel the Truman administration'sreconsiderationof war powers in the early Cold War it examines three aspects of the executive branch's current understandingfor tensions with the strategic demands of major power conflict: the anticipated nature, scope, and duration test used to identify possible Declare War Clause limitations; the President'sexclusive authority to engage in national self-defense; and the domestic legal effects of collective defense treaties. Findingthat the anticipatednature, scope, and durationtest is likely to prove more constrainingin the context of majorpower conflict than it has for past asymmetric conflicts, this Article then surveys executive branchpracticeto identify ways it may adapt its understanding, from a return to broad claims of inherent and exclusive presidentialauthority to use force to more targeted adaptationsrelating to treaties, self-defense, and even prerogative. From there, it puts the executive branch's decision in the broader context of inter-branch relations and considers alternatives, includingthe pursuitof statutory authorization. Ultimately, it argues that the political branches must acknowledge and begin dialogue on how to approach the new strategic challenges the United States is facing. Otherwise, they risk compounding the politicalcrisis of a majorpower conflict with a constitutional crisis over how the Presidentmay respond. t Fellow in Governance Studies at the Brookings Institution; Non-Resident Senior Fellow in the National Security Law Program at Columbia Law School. The author would like to thank Matthew Waxman and the participants in the University of Chicago Legal Forum's 2023 Symposium on "Reimagining National Security" for their useful comments and feedback. He would also like to thank Saloni Jaiswal and the rest of University of Chicago Legal Forum staff for their flexibility and excellent editing, as well as his wife Elizabeth for her support and endless patience. 1 2 THE UNIVERSITY OF CHICAGO LEGAL FORUM I. [2024 INTRODUCTION The United States is no stranger to war. But in recent decades, its experience has been mostly limited to wars against substantially weaker adversaries. In the post-Cold War era, this trend has reflected the United States' hegemonic status and its focus on non-state threats to its national security. And while major power conflict with the Soviet Union or People's Republic of China was a risk for decades prior, most of the United States' military efforts nonetheless centered on smaller, regional conflicts. 1 To be certain, these asymmetric conflicts presented the United States with serious challenges. But none entailed a level of threat approaching that of a war with an enemy whose capabilities more closely rival the United States' own. This era of asymmetric conflict, however, may be over. In their respective national security strategies, both the Biden and Trump administrations have identified major power competition as an increasingly preeminent national security threat, with fears of an ascending China and bellicose Russia rapidly eclipsing the concerns over global terrorism and weapons of mass destruction that preoccupied their predecessors. 2 Once seen as an outside risk, the possibility of conflict with another major power is now at the center of the highest levels of strategic planning and raising new questions about the adequacy of the status quo. "U.S. foreign policy was developed in an era that is fast becoming a memory," incumbent U.S. National Security Advisor Jake Sullivan recently wrote in ForeignAffairs. 3 "Strategic competition [with China and Russia] has intensified and now touches almost every aspect of international politics[.]" 4 For the United States to survive and thrive, Sullivan suggests, "[o]ld assumptions and structures must be adapted to meet the[se] [new] challenges." 5 This Article considers what this shift in strategic focus from asymmetric to major power conflict may mean for one such set of assumptions and structures: the executive branch's operational understanding of constitutional war powers, specifically regarding the use of military force. Few matters of constitutional law are more hotly contested. But in recent years, the executive branch has employed an understanding of constitutional war powers that has remained relatively consistent For a detailed survey of U.S. military engagements through these periods, see generally ALLAN R. MILLETT ET AL., FOR THE COMMON DEFENSE (3rd ed. 2012). 2 See WHITE HOUSE, NATIONAL SECURITY STRATEGY 6 (2022) (Biden administration); WHITE HOUSE, NATIONAL SECURITY STRATEGY 25 (2017) (Trump administration). Jake Sullivan, The Sources of American Power: A Foreign Policy for a Changed World, FOREIGN AFFS., Oct. 24, 2023, at 2. 4 Id. Id. 1] WAR POWERS AND THE RETURN OF MAJOR POWER CONFLICT 3 across presidential administrations and has avoided serious challenges from Congress and the courts. The standards this understanding imposes are quite permissive in the context of asymmetric conflict, allowing the executive branch to justify a wide range of military action without having to secure prior congressional authorization. But in the context of major power conflict, the same standards-in particular, the "anticipated nature, scope, and duration" test used to identify possible Declare War Clause limitations 6-are likely to prove far more constraining, even on limited military actions. This is likely to be seen as a problem by senior policymakers as they wrestle with the growing prospect of major power conflict and increasingly rely on the ability to credibly threaten the use of military force to deter major power adversaries. How this tension will be resolved is unclear, but the consequencesboth for the separation of power (...truncated)