Description:In 1999, ten years of heated debate about the EU's role in defense policy came to an end, when the EU decided to establish an autonomous security and defense policy. Germany and Britain had been key players in the years leading to this decision. But they played markedly different roles -- the former endorsing the idea from the beginning, the latter dragging its heels and only reluctantly becoming a supporter. Nonetheless both British and German policies can be understood as responses to impulses from the international system. The end of the Cold War prompted both states to pursue a policy of balancing US power. Yet international institutions constrained their balancing efforts differently. To demonstrate this, this study builds on the theories of neo-realism and historical institutionalism and develops the approach of structure-based foreign policy analysis: a new mode of analyzing security policies as responses to the international environment.