WW2 started out with a “reasonable” claim by Germany on the small German speaking area of the Sudetenland in Czechoslovakia. Hitler got what he wanted, then he decided he wanted more. Next the world was
In flames.
The only reason Hitler thought about the Sudetenland was because the English and French completely rolled over for him on Alsace and Lorraine.
After Alsace, Lorraine and Czechoslovakia the Germans had no real idea invading Poland would actually cause a war.
Poland was just a bridge too far.
Zuck ChinA !!