Japanese militarism, appeasement, The league of Nations, and most prevalent, the political takeover of Germany by the Nazi party.
The first stem to WWII was Hitler and the Nazi Parties rise to power. They came to power because of The Treaty of Versailles, the Great Depression that began with the failure of the stock market, and the use of violence, to silence opponents, like the communists. The treaty of Versailles, can be attributed to Hitler’s rise to power, the Weimar republic, was forced to sign