Hitler was aware of the defense promises France and England made and re-iterated to Poland. He chose war.
Given the history of French and British (lack of)responses to prior provocations, and their then current level of military preparedness, war was hardly inevitable with even France and Germany; and Hitler certainly had no notion of going to war with America, never mind invading us and making German the US national language, going back to my original response to post 26.
As I've stated earlier you can make the case for US participation in the War in a Make the World Safe For Democracy Version II way; but the way in which we entered and finished the war put American strategic interests; and human rights around the world in a much worse position.
By the way, Buchanan is on the air right now (4:10 Eastern time) on the Howie Carr Show WRKO.com, where you can listen now to Pat talking about this.
And, he called their pitiful bluff.