Rational war and constitutional design

Contemporary accounts of the allocation of war powers authority often focus on textual or historical debates as to whether the President or Congress holds the power to initiate military hostilities. In this Essay, we move beyond such debates and instead pursue a comparative institutional analysis of the relationship between Congress and the President on war powers. More specifically, we ask which war powers system would best enhance the effectiveness of the United States in making decisions about war and peace? First, we suggest that the argument that a Congress-first approach will have clear political accountability and accuracy advantages over a President-first approach rests on questionable empirical and theoretical assumptions. Second, we turn to the international dimension and draw on one of the few facts considered to be close to an empirical truth in international relations: Democracies do not tend to go to war with each other. Here, we explore the relationship between the regime type of the adversary and the war powers system best suited to combating it. We argue that if the United States were involved in a dispute with another democracy, involving Congress could help facilitate a peaceful resolution by allowing the United States to signal more effectively its intentions. If, however, the United States were involved in a dispute with a nondemocracy or a terrorist organization, a unilateral presidential approach would make more sense because such an opponent is less likely to have the proper incentives to respond to the signal conveyed by congressional participation. Finally, we conclude that only an approach that vests exclusively in the President the discretion to seek ex ante congressional authorization would permit the United States to adapt its domestic decision-making structure to the exogenous demands of the international system.