The Soviet Invasion of West Germany was a Soviet military operation in Western Germany taking place on December 3rd, 1962 and is generally seen as the catalyst for World War III. The invasion occurred following an armed standoff between Soviet and American forces near Cuba. The invasion began by surprise and without declaration of war by the Soviet Union. Armed response by NATO followed. Many Warsaw Pact nations helped the Soviet Union, with East Germany acting as a springboard for Soviet troops.