When was the Nuclear arms race?

1939 to 1989

The race began between Nazi Germany and England in 1939. The USSR began spying on the work in England.

Nazi Germany quietly withdrew about 1942 as the US entered and took over the work from England.

The US completed the first atomic bombs in 1945.

The USSR completed their first atomic bomb using info from their spies in 1949.

The nuclear arms race between the US and USSR officially ended in 1989.