Well, they didn’t fear Nazi Germany up until the point where it became clear that war was inevitable. Chamberlain’s “Peace for our time” was the order of the day way before “Very well: alone” and “Keep calm and carry on”.
Up until Germany started its takeover of Europe, their thinking was very much like liberals’ attitude toward Islam today: you can appease the devil by being nice and he’ll be nice to you in return. But they were in for a surprise because their idealism doesn’t work in the real world. Never has, never will. They don’t know that because they’re always trying to change history instead of learn from it.