Yugoslavia was a socialist state but not an Eastern Bloc country. In 1948 following the Tito-Stalin split Yugoslavia broke ties with the Soviet Union and its allies, and during the Cold War, it was one the leading members of the Non-Aligned Movement. After the Soviet Invasion of Czechoslovakia in 1968, the concerns about an eventual Soviet attack started to rise within the Yugoslav leadership. The invasion of Czechoslovakia showed that the standing conventional forces of a small country could not repulse a surprise attack by a qualitatively and quantitatively superior aggressor. Being strategically positioned between the two major blocs, the NATO and the Warsaw pact, Yugoslavia had to prepare its own military doctrine for an eventual Third World War scenario.