From Wikipedia
Cold War
Episode Twenty
During December 1979, approximately 75,000 Soviet troops invaded Afghanistan in order to support the Marxist government formed by ex-Prime-minister Nur Muhammad Taraki, assassinated that September by one of his party rivals. As a result, US President Jimmy Carter withdrew the SALT II treaty from the Senate, imposed embargoes on grain and technology shipments to the USSR, demanded a significant increase in military spending, and further announced that the United States would boycott the 1980 Moscow Summer Olympics. He described the Soviet intervention in Afghanistan as "the most serious threat to the peace since the Second World War"

This map shows the two essential global spheres during the Cold War in 1980–the US in blue and the USSR in red. See the legend on the map for more details.