When the Soviets tested their first atomic bomb in 1949, it was game on. President Harry S. Truman responded by announcing that the United States would build an even more destructive weapon: the hydrogen bomb. Stalin followed suit and the "arms race" began.
In retrospect, the Cold War put up some very impressive stats. Alltime Numbers, a YouTube channel dedicated to crazy facts and stats on pretty much any topic created the following video about the Cold War in numbers, and the facts are chilling. For example, the video opens with: "The world's first hydrogen bomb had the power of 10.4 million tons of TNT." By comparison, the atomic bomb dropped on Hiroshima had the power of 12 - 15,000 tons of TNT.