How did the development of the atomic bomb affect the World War 2 and cold war?

The development of the atomic bomb significantly impacted World War II by leading to the swift conclusion of the conflict after the U.S. dropped bombs on Hiroshima and Nagasaki, forcing Japan's surrender. This introduction of nuclear weapons also marked the beginning of the Cold War, as the U.S. and the Soviet Union entered an arms race to develop their nuclear capabilities, fundamentally altering global power dynamics and military strategies. The threat of nuclear warfare established a tense geopolitical landscape characterized by deterrence and the doctrine of Mutually Assured Destruction (MAD).