government there. When North Korean forces invaded the south in 1950s, the United States led allied forces against the Communist north. After three years of fighting the Korean War came to an end. The peninsula was divided into North and South Kor Later in that decade the Soviets spread their influence to Indochina. After the French had been thrown out of Vietnam in the 1950s the country was divided into a Communist north and a free south. North Vietnam, however, wanted to unite Vietnam under Communist rule. Soon the Americans got involved in the war on the side of the South Vietnamese. After a decade of fighting, the Americans and South Vietnamese were defeated and the Communists reunited the country. In 1979 the Soviets invaded Afghanistan in an attempt to stop Islamic influence from spreading to their southern borders. Arms and Space Race Four years after the atomic bomb had been dropped over Hiroshima and Nagasaki, the Soviets exploded their first atomic bomb and became a nuclear power. During the decades of the Cold War both countries increased their nuclear stockpiles. They developed intercontinental missiles which could reach all corners of the world in a short time. During the 1970s each country had enough nuclear weapons to wipe out all life on earth. Later on, they agreed to stop the arms race and set a limit to the number of weapons each country had. The Soviet Union and the USA extended their rivalry in what became known as the space race. Both superpowers wanted to demonstrate their technological superiority. In 1957, the Soviets launched the first satellite into space and in 1961 Yuri Gagarin became the first human to orbit the earth. The space race ended in 1969 when Apollo 11 landed on the moon. End of the Cold War The latter half of the 1980s slowly brought an end to the Cold War. In the Soviet Union Mikhail Gorbachov took power. He wanted to open up the economy of the largest country on earth. His policy of glasnost and perestroika aimed at giving the Soviet population more freedom and rights. In 1989 Communism started to collapse in many parts of Eastern Europe. In November 1989 the Berlin Wall was torn down and East Germans were allowed to travel freely to the West. In 1991 the Soviet Union ceased to exist and broke up into 15 independent countries. Communism survived in only a few countries, including Cuba.