One of the most striking features of the ‘war on terror’ has been the support given to the US by a number of key allies like Australia and Britain. Some observers see this as a form of ‘bandwagoning’ in the face of overwhelming American dominance. And yet, not only is American hegemony far less certain of late, but Australia and Britain participated despite rather than because of any immediate benefits. Moreover, some of the US's key rivals like China appear to have benefited by not aligning themselves with the US. This article argues that bandwagoning, both as a theory and as a rationale for policy-making, is inadequate. Consequently, we need to look at more contingent and specific factors if we want to understand the behaviour of America's allies and rivals.