The end of the cold war has produced a sustained debate on international relations theory. Some scholars argue that the unexpected and unexpectedly peaceful demise of the post-World War II international order undermines the entire research agenda of the subfield; others maintain that it warrants an adjustment of the balance between theories or theoretical traditions; and still others hold that it has little or no relevance to theory. This essay reviews the debate in light of the new evidence that has accumulated over the past five years. It finds that because scholars rarely make the empirical implications of their arguments explicit, the cascade of new information concerning the event cannot advance the debate. However, the natural focus provided by a sudden and unexpected event of seminal importance and the outpouring of new data suggest the possibility of empirically driven progress in one's understanding of change in world politics. The article concludes with guidelines designed to increase the likelihood of such progress by clarifying the debate in advance of new releases of primary data.