sentences:  Overall, the number of international wars decreased from a rate of six per year in the 1950s to one per year in the 2000s, and the number of fatalities decreased from 240 reported deaths per million to less than 10 reported deaths per million.Major factors cited as reasons for the Long Peace have included the deterrence effect of nuclear weapons, the economic incentives towards cooperation caused by globalization and international trade, the worldwide increase in the number of democracies, the World Bank's efforts in reduction of poverty, and the effects of the empowerment of women and peacekeeping by the United Nations.However, none of these are sufficient explanations on their own, so additional or combined factors are likely.