Although a perennial feature of global politics, separatist movements had scant prospect of success for nearly half a century after World War II. And so the recent proliferation of new states has shattered settled expectations. In the 1990s, Yugoslavia fractured into five states, the Soviet Union split into fifteen, Eritrea separated from Ethiopia, Czechoslovakia divided into the Czech Republic and Slovakia, and East Timor won independence from Indonesia. The success of breakaway movements from Slovenia to Eritrea has given new impetus to a raft of other separatists across the globe. And small wonder: the surge in state making in the 1990s marked a new departure. Outside the context of decolonization, international law has long regarded separatist claims with disfavor. To be sure, international law and state practice remain deeply skeptical of separatist movements; few are likely to succeed. Even so, the recent success of several signifies the possibility of a broader realignment of law and policy.