As World War II transformed both the United States and the USSR, turning the nations into formidable world powers, competition between the two increased. Following the defeat of the Axis powers, an ideological and political rivalry between the United States and the USSR gave way to the start of the Cold War.

The Cold War was the war between the USSR and the USA which never actually came to direct fighting. Both tried to impose their ideologies on other countries – communism and capitalism – and gain superiority by the use of propaganda, espionage and the vast stores of weapons.

The alliance between the United States and the Soviet Union during World War II developed out of necessity, and out of a shared realization that each country needed the other to defeat one of the most dangerous and destructive forces of the twentieth century.

World War II was one of the transformative events of the 20th century, causing the death of 3 percent of the world’s population. Deaths in Europe totaled 39 million people — half of them civilians. Six years of ground battles and bombing resulted in widespread destruction of homes and physical capital.

The Hiroshima Bombing Didn’t Just End WWII—It Kick-Started the Cold War. The colossal power of the atomic bomb drove the world’s two leading superpowers into a new confrontation.

Historians have identified several causes that led to the outbreak of the Cold War, including: tensions between the two nations at the end of World War II, the ideological conflict between both the United States and the Soviet Union, the emergence of nuclear weapons, and the fear of communism in the United States.

During WWII, the US bombed Germany with conventional bombs for years. The only reason that the US did not use the atomic bomb against Germany was because the A-bomb was not ready when they officially surrendered. Germany surrendered to the allies on May 7, 1945.

In 1949, the USSR tested its first atomic bomb. This led to a race between the two superpowers to amass the most powerful nuclear weapons with the most effective delivery systems. Tension was greatly increased as a result of the developing arms race which served to militarise both sides and bring war closer.

President Harry S. Truman learned on this day in 1945 of a successful test — two days earlier — in the New Mexico desert of the world’s first atomic bomb. He told Truman that he hoped the Americans would put it to good use against the crumbling Japanese empire. …

As made by Gar Alperovitz more than forty years ago, the original revisionist argument maintained that the atomic bomb was used primarily to intimidate the Soviet Union in order to gain the upper hand in Eastern Europe and to keep Moscow out of the war in the Far East. Revisionism’s heyday lasted until the 1990s.

Japan surrendered because the Soviet Union entered the war. Japanese leaders said the bomb forced them to surrender because it was less embarrassing to say they had been defeated by a miracle weapon. Americans wanted to believe it, and the myth of nuclear weapons was born.