Although wars between even small nations are tragic for the populations involved and can cause wider problems in the international system, the prospect of armed conflict between major powers is the true nightmare scenario—especially in an era of nuclear weapons. The two world wars that so horribly scarred the twentieth century provide important reminders of the dire consequences of great-power conflicts. It follows that all responsible major countries should avoid actions that increase the risk of needless confrontations. Unfortunately, the level of danger from such conduct appears to be rising rather than declining.