Which event marked the start of significant aerial warfare tactics during World War II?

The invasion of Poland in September 1939 is recognized as a pivotal moment that marked the beginning of significant aerial warfare tactics in World War II. During this campaign, the Luftwaffe (the German Air Force) demonstrated how air power could be integrated into ground operations, a strategy known as the Blitzkrieg or "lightning war."

In this conflict, German forces utilized swift aerial bombardments to disrupt communication, supply lines, and troop movements of the Polish army. The effective coordination between air and ground units allowed for rapid advances and contributed to the quick defeat of Poland, showcasing the critical role that air power would play throughout the war. This event illustrated the transition towards modern warfare, in which air superiority became essential for the success of ground operations, setting a precedent for the aerial strategies that would dominate later battles of the conflict.

In contrast, while the other options include significant events of World War II, they did not initiate the widespread implementation of aerial tactics to the extent seen during the invasion of Poland.