Known as the Cold War, this conflict began as a struggle for control over the conquered areas of Eastern Europe in the late 1940s and continued into the early 1990s. Initially, only the United States possessed atomic weapons, but in 1949 the Soviet Union exploded an atomic bomb and the arms race began.
the Russian's had made nuclear weapons to destroy Americas monopoly on them, it was done so that communist states wouldnt be at threat from NATO and other nations. Although to merely compete in the cold war is untrue as many nations who competed in the cold war had no such weapons, for example west Germany was a major holding point for NATO, same goes for Hungary in the eastern BLOC.
I'm not sure if this is the answer but I think it was because they never experienced the violence that they were giving people. Sorry if this doesn't make sense but I tried. :)
