Dissertation Research

 Congressional-Executive Relations and the Use of Military Force

In virtually every military crisis encountered by the United States, questions of the authority under which the president is acting (and whether the legislature should grant some kind of authorization) are heavily debated in Congress and in the press. Despite this, political science has given little attention to the war powers debate in domestic politics and even less to the effect such internal discussion has on perceived American credibility internationally. This project proposes a theory of how the war powers have worked in actual practice since the end of the Second World War, and then demonstrates the explanatory value of the theory through both quantitative and qualitative evidence. In contrast to the conventional wisdom of an "imperial presidency" and the irrelevance of congressional war powers since 1945, this project suggests questions of war powers have consistently featured prominently in both executive branch decision-making and in the perceived credibility of American threats in the eyes of U.S. allies and adversaries. 

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 Chapter One--In the Shadow of Congress

Skeptics of congressional influence in American use of military force decisions cite, among other things, (1) the existence of a large standing military, (2) judicial unwillingness to adjudicate war powers cases, and (3) congressional incentives to allow the president to use military force absent formal approval as contributors to an imperial presidency virtually unchecked in the war powers context. This chapter argues that---even assuming all of these maladies as a given--Congress can still exert substantial influence over use of force decisions by shaping expectations of political punishment for deployments that turn out poorly. Analogous to the dichotomy between defense and deterrence-by-punishment, while Congress has little ability to affect a president's ability to use force, it maintains a substantial capacity to affect their willingness to do so. Using a formal model, it is shown that this threat of ex post punishment by the legislature not only affects presidential decision-making, but also affects international perceptions of U.S. credibility. The theory additionally suggests that even if presidents are indeed substantially strategically constrained in their decision-making by congressional concerns, they have strong incentives to nonetheless bluff a willingness to act imperially. 

 Chapter Two--Quantitative Assessment

While pundits and legal academics often bemoan a supposed lack of congressional influence in war initiation decisions,  political scientists have provided evidence that congressional composition seems to affect both the willingness of presidents to use military force (Howell & Pevehouse 2007, Kriner 2010) and the credibility adversaries give to presidential threats (McManus 2017). Studies in political science have thus far, however, only been able to employ very rough proxies for congressional support for possible uses of military force, such as the number of co-partisans a president has in Congress (Howell & Pevehouse 2007, Kriner 2010) or the number of Republican legislators (McManus 2017). This measurement limitation likely substantially underestimates congressional influence on military force decision-making. This chapter attempts to create a much more direct measure of congressional sentiment over possible military intervention by utilizing both human coding and supervised machine learning text analysis to measure the policy preferences advocated for by legislators in roughly one hundred crises since the Second World War. Preliminary findings suggest that it is actually quite rare for presidents to undertake military actions opposed by Congress---and that those instances that do exist are quite small in scale.

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 Chapter 3--The Korean War Anti-precedent

Scholars of the American war powers frequently cite the Korean War as a watershed precedent created when Truman classified the intervention as a mere “police action” not requiring congressional approval. More often overlooked, however, is the political anti-precedent the Korean case has served in presidential decision-making since Truman’s decision. Indeed, in the seventy years since the outbreak of the Korean conflict, there has never again been a major U.S. conflict undertaken unilaterally by the president. Using archival research and qualitative process tracing methods, this chapter argues that this lack of unilateral full-scale war is not a coincidence but, rather, because Truman’s successors took a specific lesson away from the Korea War: by failing to have members of Congress publicly commit to armed intervention ex ante via a formal vote, they left themselves vulnerable to highly damaging congressional action ex post if the use of force did not end in victory. Examining fourteen postwar crises, we find clear evidence that presidents subsequent to Truman consistently saw the Korean War as an example to be avoided, and instead viewed undertaking major conflict unilaterally as so risky politically as to make it simply unfeasible. 

 Chapter Four--A Watching World: The War in Vietnam

While the preceding chapter focused on decision-making internal to the United States, this chapter extends the analysis to also focus on the watching world abroad. The Vietnam War is selected as a “least likely” case against which to test the theory. The period from the beginning of the Cold War until the end of the Vietnam War and the passage of the War Powers Resolution in 1973 is considered the zenith of the Imperial Presidency. When contemplating the use of military force in Southeast Asia in the 1950’s, 60’s, and 70’s, presidents possessed both a massive standing military and the clear example of Truman's "police action" in Korea as a precedent. Using archival research---including primary sources in both Chinese and Vietnamese---this chapter examines (i) congressional influence on presidential decision-making, (ii) international perceptions of American credibility based on congressional behavior, and (iii) White House concerns about international perceptions of American credibility based on congressional behavior. Looking at twelve separate crises---from the 1954 siege of Dien Bien Phu and Geneva Conference to the 1975 Fall of Saigon and Mayaguez incident---evidence generally supports the expectations of the theory and contradicts the imperial presidency thesis.