Post-crisis international standards have been agreed on in certain areas of banking regulation, namely capital, liquidity, and resolution, but not others, namely bank structure – why? We articulate a two-step analytical framework that links the domestic and international levels of governance. In particular, we focus on the role of domestic regulators at the interface between the two levels. At the domestic level, regulators evaluate externalities and adjustment costs before engaging in cooperation at the international level. This analysis explains why regulators in the United States and the European Union act as pacesetters, foot-draggers, or fence-sitters in international standard setting; that is to say, why they promote, resist, or are n...