Hitler's decision to attack the West was ideological and irrational, and his own high command planned a coup in November 1939 to stop him ordering it.

His officers didn't think so. High command said, “No, we're not going to attack the West; we're going to lose.” And Hitler was fanatic about it, he really wanted to attack it. They were planning a coup against him in November 1939 just to prevent him ordering the attack on the West, because it would have been a catastrophe for Germany.