1. As we explain in chapter 3, treaties, unlike customary international law, can never reflect pure coincidence of interest.
2. Swaine (2002) argues that these factors can be overcome because states care about their reputation for complying with international law. We address this and other reputation-based arguments for compliance in part 2.
3. The model for such an argument would come from evolutionary game theory (see H. Young 1998, 25–90). This model shows that as long as parties either experiment or occasionally make errors, and as long as they interact frequently, they will eventually coordinate on Pareto-optimal actions. “Eventually,” however, may be a very long time, and the games the model uses rely on institutional structure that is lacking with respect to customary international law. For an evolutionary approach to customary international law, see Chinen (2001).
4. For criticisms of our argument, see Swaine (2002), Chinen (2001), Guzman (2002a), and Norman and Trachtman (2004). Swaine, Guzman, and Norman and Trachtman offer rational choice theories of customary international law that could explain a more robust degree of cooperation; however, their stronger theories are not supported by the evidence of customary international law that we discuss in chapter 2.
1. Some prize courts stated during and just after the war that free ships, free goods was a rule of customary international law. See, for example, The Marie Glaeser (1914, 53–54, dicta). But most of these cases read free ships, free goods