After which Cold War event did the United States and the Soviet Union enter a nuclear arms race?
O A.
Mao Zedong's newly founded People's Republic of China formed an alliance with the Soviet Union.
O B.
Korea was divided at the 38th parallel into two parts.
• C.
Communist leader Kim II Sung prepared the North Korean army.
O D.
The Soviets detonated their first atomic bomb in 1949.
E.
John Dulles, US secretary of state, introduced the policy of brinkmanship.