I've had a chat with some of my buddies about the beginning of WW2 - specifically, when did it begin? We all knew that September 1st, 1939 was the 'official' beginning of the war, since this is the date most historians agree upon, but I was still not convinced.
Here are the number of options for you to choose from, and my explanations:
1.1931, September 18. Mukden Incident. Japan invades Manchuria and establishes a puppet state there, Manchukuo. This may seem harmless, but this is the beginning of Japanese meddling in the Chinese remains of the Qing dynasty.
2. 1937, July 7-9. Marco Polo Bridge Incident, which sparked the incursion of Japan into Chinese soil and the Sino-Japanese war which only ended in '45.
3. 1938, March 11, Annexation of Austria.
4. 1935, October, Italian-Ethiopian war.
5. Invasion of Poland by Germany, 1939, September 1.
6. Pearl Harbor bombing. 1941, 7-8 December. 8th of December had the USA officially enter the war.
7. 1938, 30 September. The betrayal at Munich, where Czechoslovakia was royally screwed by its allies.
We had three dates in mind, but because I didn't want the thread to be about our discussion I also added 4 more dates to the mix. They may seem like the stepping stones towards WW2... you're probably right. Still, aggression can also be manifested in diplomacy.