During the Cold War, both the US and Russia made great leaps in building up their arsenals with not only new technologies, but also with weapons of mass destruction. During this time period, both countries began developing new weapons technology and reconnaissance technology. As shown by the graph on the left, between 1945, throughout the entire Cold War and into the early 2000's, both the US and USSR each gathered over 30,000 nuclear bombs and were prepared to use them if need be.