  When the Cold War division of the world made a global competition law regime impossible, the US as the dominant economic and political power in the non-Communist world took responsibility for dealing with threats to transnational competition. Since then, US law and institutions have provided the basic rules of competition on transnational markets. This chapter analyzes the principles of international law that have been the basis for this regime and traces its evolution during the second half of the 00th century. This regime relies on national laws to provide competition rules, but few states have sufficient political and economic leverage to apply their laws outside their own territory, and this allows the US (and, to a lesser extent, the EU) to provide these conduct rules. Jurisdictional authority  -  and the interests, expectations and attitudes associated with it  -  remain the central component of the legal framework for global competition.