Who Killed Article 38(1)(b)? A Reply to Bradley and Gulati

Curtis Bradley and Mitu Gulati's provocative article on "Withdrawing from International Custom," 120 Yale Law Journal (2010) (forthcoming), shines light onto a central yet under-analyzed issue of customary international law and brings to bear thought-provoking research and analysis. Ultimately, however, the proposal that states should be able to individually withdraw from international custom as they often can from treaties is unconvincing and concerning because (1) it is based on questionable analogies between custom, on the one hand, and treaties and contract law, on the other, and (2) when understood in its real world context, rather than in the academic laboratory, it has the potential to facilitate opportunistic and abusive claims that undermine the interests of the international community.