Why did the Soviets not take Austria?

The Soviets did invade, but not all of Austria. In April of 1945, the Soviets invaded Austria, which had been part of Germany since the Anschluss in 1938. By mid-April, the Soviets had taken Vienna. However, their offensive then stopped. read more

As to why both parties agreed not to partition Austria it is probably because Austria is a tiny country with a tiny population, splitting it would make it even tinier so unlike Germany splitting it was of no benefit. Also the Soviets saw how hard it was to control East Germany in terms of stopping East Germans from trying to escape to West Germany. read more

The Soviets and the Western allies did not dare to actively intervene in the strikes. The strike intensified the militarization of Western Austria, with active input from France and the CIA. Despite the strain of the Korean War, by the end of 1952 the American "Stockpile A" (A for Austria) in France and Germany amassed 227 thousand tons of materiel earmarked for Austrian armed forces. read more