What significant event did the Nazi-Soviet Non-Aggression Pact enable Germany to undertake?

The Nazi-Soviet Non-Aggression Pact, signed in August 1939, was a pivotal agreement between Germany and the Soviet Union that allowed both countries to avoid conflict with one another while they pursued their respective territorial ambitions. One of the significant implications of this pact was its facilitation of Germany's invasion of Poland on September 1, 1939.

With the assurance that the Soviet Union would not intervene, Germany was able to launch a military campaign against Poland without fearing a two-front war, a strategic concern that had plagued German military planners since World War I. This invasion marked the beginning of World War II in Europe, as it prompted Britain and France to declare war on Germany shortly afterward.

The context around the other options highlights why they do not hold the same significance as the correct answer. The annexation of Austria had already occurred in March 1938, well before the pact was signed. The declaration of war on France came later, in September 1939, following the invasion of Poland, not as a direct consequence of the Non-Aggression Pact. Finally, while the pact did facilitate relationships that would lead to the formation of the Axis alliance, this was not its most immediate outcome, nor is it the event most