Posner and Goldsmith on "The Limits of International Law"

The day before last week’s ASIL meeting, AEI hosted an excellent panel discussion of the book “The Limits of International Law” by Professors Eric Posner and Jack Goldsmith. A transcript of the discussion is here. The Posner/Goldsmith thesis is based on rational choice: States should engage in international law making or agree to comply with pre-existing international legal norms in order to promote their national interests. Posner and Goldsmith distinguish their theory (only slightly, perhaps) from international relations realists by recognizing that national interests can be broader than just maximizing power or security. But at bottom, Posner and Goldsmith posit that international law is an expression of states acting rationally to promote to their national interest. Any cooperation among states is a byproduct of that rational act. This is an intuitive and very useful framework for explaining both why states enter treaties and why they may later breach them. But it has limits.

While Posner and Goldsmith claim that they are not suggesting that international law is meaningless or that international law does not exist, that is not an unreasonable conclusion to draw from their thesis. As David Scheffer pointed out in the discussion, if the claim is that states only act rationally in their national interest, and if a state decides that international law is not part of its national interest, is there international law? Douglas Ginbsburg had a different twist: if international law is nothing more than states acting in their rational self-interest, it appears to be some sort of device through which politics can be carried out, but does not have the full attributes of law.

Further, the thesis is limited by its necessary reliance on a rather monolithic view of “national interest.” Interestingly, this critique comes from both the right and the left. The right takes seriously the moral underpinnings of liberal democracy and believes expression of that morality has a place, for example, in the United States’ national interest. For the liberal institutionalists, the rational choice hypothesis fails to consider the complexity of state interests and the various constituencies (including minority views) that are reflected in a state’s participation in international legal regimes. And it also fails to consider how international law and institutions themselves are integrated into and affect notions of self-interest at the domestic level.

That said, the book is a useful framing device through which to test and examine other theories of international law.