6.1 Nuclear Age

Learning Target 23: Summarize how atomic weapons have changed the nature of war, altered the balance of power and started the nuclear age.

Following World War II, the United States and the Union of Soviet Socialist Republics (Soviet Union) emerged as the two strongest powers in world affairs. The U.S. and Soviet Union had opposing political and economic ideologies. The U.S. was democratic and capitalist. The Soviet Union was communist. From 1945-1991, the two nations challenged one another in a series of confrontations known as the Cold War.

During World War II, the U.S. began a secret program, known as the Manhattan Project, to develop atomic weapons. The first atomic bomb was dropped on Hiroshima, Japan on August 6, 1945. This was followed by the dropping of the second atomic bomb on Nagasaki on August 9. The dropping of atomic bombs on Japan led to the rapid end of World War II in the Pacific. (The War in Europe had already ended in May.)

The use of atomic weapons changed the nature of war, altered the balance of power and began the nuclear age. The dropping of the atomic bombs in Japan is considered the beginning of the nuclear age. The use of these bombs introduced a new type of weapon capable of mass destruction. 

For four years following World War II, the United States was the only country in possession of atomic bombs. This contributed to its status as a global superpower. The threat of using this weapon was seen as a deterrent against the ambitions of the Soviet Union.

​The testing and explosion of the atomic bomb by the Soviets in 1949 established the Soviet Union as a second global superpower. In 1952, the U.S. tested its first hydrogen bomb. Three months later, the Soviet Union tested its first thermonuclear bomb, and by using lithium, they made a bigger bomb small enough to fit into a plane. This nuclear arms race continued for decades and threatened world peace.