Photon:

Well, the 1930s aren’t very parallel, b/c the Brits weren’t at war yet. Just as we ignored WTC ’93, the Cole, Khobar Towers, Tanzania/Kenyan embassy bombings, so they ignored Spain, Rhineland, Anschluss, etc.

But the desire of Churchill to get Britain into an “unnecessary” war over the Sudetenland is, I think, where the parallel begins: the arguments against preemption, thinking about “root causes” (e.g., German rights to reunify their peoples in places like the Sudetenland). It’s useful to remember that there were no death camps (as opposed to concentration camps) in 1938-1939 just yet. (Dachau, iirc, was established in 1938.)

9-11, however, brings us to 1939 Britain. The war is here, whether you want it to be or not. And Britain was not unified, however much Brits would like to think it was in retrospect, any more than “everyone” opposed German anti-Semitism.

Indeed, as I noted in referencing Lukacs, the collapse of the British position at Dunkirk led to one of the first crises of the Churchill government, w/ Lord Halifax (and the British upper classes) arguing that this provided an opportunity for a negotiated peace with the Germans. Churchill, “war-monger” that he was, of course, opposed this.

Nor would this be the last time. While exactly WHAT was going through his mind is unclear, Rudolf Hess’ flight to Britain was apparently intended to extend some kind of feeler to upper class Brits in the hope that they might want to end the war sooner. (Interestingly, many novels have suggested that Edward VIII might have been willing to head such a regime, but it’s less clear whether that’s history or plot device.)

Nor was Churchill’s position all that secure. 1941 saw several disasters, including the collapse of British forces in North Africa, and much later the loss of British warships culminating in the fall of Singapore, all of which aroused serious questions about his wartime leadership. IIRC, Churchill faced an outright no-confidence vote then, and another in 1942 with the fall of Tobruk. Churchill enjoyed the support of the man in the street (interesting, given his patrician background and Conservative leanings), but not necessarily that of the monied upper classes.

Even today, some of the upper classes argue that Churchill was precisely wrong to have insisted on fighting, that a modus vivendi could have been reached. See John Charmley, for example.