The United States and Soviet Union started creating bombs
Who: United States and the Soviet Union.
When: during the Cold War august 29 1949.
Why: Russia wanted the spread of communism and the United States wanted the spread of capitalism they wanted to kill each other and hated each other.
What: United States and the Soviet Union hated each other and wanted to kill each other so they started developing new weapons like guns bombs and submarines but then they started losing all of there money for all of the weapons so the economy started going down they spent about 27% of there money worth of bombs and stuff.
Were: Russia and the United States.
The arms race ended when the Soviet Union collapsed at the end of the Cold War in 1991.