Some people said that one of the main causes of ww2 is treaty of versailles, but ww2 was about Britain and France declaring war on Germany when Hitler wanted to invade Poland, and treaty of versailles was used for punishing Germany after ww1, I just don't understand. Maybe I'm kinda stupid, so please tell me in detail why it is related to ww2 and how it caused ww2, thank you very much!!