Answer:
The Cold War began after the surrender of Nazi Germany in 1945, when the uneasy alliance between the United States and Great Britain on the one hand and the Soviet Union on the other started to fall apart. The Americans and the British worried that Soviet domination in eastern Europe might be permanent.
Armored vehicles, submarines, and missiles saw huge gains in effectiveness. Nuclear weapons in particular were made smaller and exponentially more powerful.
Step-by-step explanation:
Hope this helps! -C.E.M.