Afghanistan was viewed as important neighbour by the Soviet Union. It was also seen as an important buffer between the Soviet Union and Iran. The Soviet Union did not want Islamic fundamentalism to spread along its borders.
The Kabul Revolution of April 1978 witnessed the dramatic overthrow of the Afghan family. There was a new government that was determined to "build socialism in Afghanistan." Mohammed Taraki introduced new communist style reforms and Muslim intellectuals were imprisoned,tortured or murdered.
Taraki's position was threatened by Hafizullah Amin, the deputy prime minister who seized power in September 1979. How ever Amin continued with the Anti-Muslim policies and thousands of muslims joined mujahideen
Amin began to form alliances with the USA, this brought suspicions and accusations of him being a spy. Brezhnev therefore allowed an invasion following the Prague spring. On Christmas day, he sent more than 50,000 Soviet troops to invade Afghanistan. They remained for 10 years, around 1.5 million people died.
The US President Jimmy Carter was appalled by the Soviet Aggression and responded with the Carter Doctrine. The US reaction was swift and immediate. The US congress also refused to ratify SALT II. IN his speech to the people of America he made it very clear he would try to stop the spread of communism.
Carter withdrew his support from SALT II. As a protest the USA even refused to go to he Moscow olympic games in 1980. They set up their own olympic games called the Boycott Olympic games. The mascot for Russia was nicknamed the Gulag Bear. As a retaliation the USSR created the Friendship Games.