Scholarship on foreign affairs law - the body of law, mainly constitutional, that governs the foreign affairs of the United States - reflects a striking divide between the courts and the academy. In the courts, the dominant judicial approach to foreign affairs law is "executive primacy" - the view that judges should defer to the executive's judgments about foreign affairs. In the academy, the dominant approach is what we will call "foreign affairs legalism." Foreign affairs legalism holds that courts should impose more restrictions on the executive than they have in the past or that Congress should play a greater role in foreign affairs. This normative argument rests on two usually implicit descriptive premises: that courts and Congress have the capacity and motivation to restrain the executive, and that the courts and Congress will do so for the sake of promoting international law.

This disjunction between academic and judicial thought matters today more than it ever did in the past. The conflict with al Qaeda has generated an enormous quantity of jurisprudence, including some cases that reflect a new legalist sensibility in tension with the old commitment to executive primacy. Globalization has produced more cross-border conflicts involving trade, migration, human rights, and investment - and the debate between executive primacy and foreign affairs legalism will help determine how courts handle these conflicts.

Despite its prominence in the academy, there is no official school of foreign affairs legalism; no single scholar explicitly defends it. Much of the foreign affairs scholarship of the last twenty years advances this account, however; but the problem is that the argument is mostly implicit. In this Article, our minimal goal is to tease out the distinctive empirical and normative assumptions of foreign affairs legalism. We also argue, more ambitiously, that foreign affairs legalism rests on unproven and inaccurate assumptions about the capacities and motivations of courts and the executive, and it reflects confusion about the nature of international law. Of particular importance, foreign affairs legalists falsely assume that the judiciary seeks to advance international law while the executive seeks to limit it.

In Part I, we describe foreign affairs legalism as it manifests itself in the work of a few representative scholars. In Part II, we describe the weaknesses in this account and propose an alternative approach to foreign affairs law. We conclude that our approach, which supports executive primacy, promotes the continued development of international law.