This major new global survey of long-term trends in war and civil conflict, sponsored in part by the Canadian government, yields some surprising results. It is widely believed that the end of the Cold War ushered in an era of spiraling armed violence and civil war. In fact, this report finds the opposite: the Cold War decades were actually quite bloody, and since the early 1990s, the number of armed conflicts, civil wars, successional struggles, international crises, acts of genocide, and arms transfers has dropped significantly. The number of international wars, military coups, and conflict deaths has also been in decline, as have refugee flows and human rights abuses in the developing world. (The one form of political violence that has not fallen is international terrorism, although the data are contested.) Equally interesting, but more debatable, is the report's explanation for this good news: the major causes of collective violence from 1946 to 1991, anticolonialism and Cold War geopolitics, disappeared with the fall of the Soviet Union, which has also allowed the UN to ramp up its involvement in conflict prevention, peacemaking, and postconflict peace-building activities. The causal claims in this argument need to be explored and debated -- but regardless, the report's good news is quite remarkable.