‘All competition laws will have to be like US antitrust law. It is the model we will all have to follow’. Such comments have been common in competition law (a.k.a. antitrust law) circles around the world for decades. The substantive elements of the US antitrust law model—in particular, the reliance on economics as the source and measure of competition law norms and a focus on consumer welfare as the sole goal of competition law—have been widely viewed as a model by students, scholars, practitioners, and administrators in many competition law regimes. The model’s influence on foreign developments is well enough known, but its role as the centre of a system of relationships among competition laws around the world is less often noticed. This system is, however, likely to be an important factor in the ‘realignment’ of US antitrust law that is the theme of the current symposium. Most discussion of realignment issues in the US look almost exclusively at domestic factors, but this view misses much of its importance. My objectives here are: (i) to highlight key characteristics of the model-centred global system and (ii) to identify its potential impact on the realignment of US antitrust law.1