Today, a world free from nuclear weapons would be a safer world, and a United States within a nuclear-weapon-free world would be a safer country. Yet nuclear weapons cannot be uninvented. Two nuclear weapons used over Hiroshima and Nagasaki killed one-quarter of a million people. Since then, however, nuclear weapons have not been used in anger, and arguably, the existence of nuclear weapons has deterred major world wars since 1945. But during this time period, there have been about 100 armed conflicts.