Chamberlain brought the reputation on himself. Diplomacy in the sense of Will Rogers’ maxim would have been to go to Munich, quietly buy as much time as possible by selling out the Czechs, and then go home and immediately put British industry on a war footing as much as possible while getting the colonial mess sorted to deal with war (both things happened. but only after war was declared). Appeasement is going to Munich, coming back waving a piece of paper at the newsreel cameras as “proof” that Hitler is a reasonable fella who’s not at all interested in war and expansionism, and then doing dick-all over the next year to prepare for the second war to end all wars.
If anti-Semitism is the “socialism of fools” then appeasement is the pacifism of fools – especially entitled and privilege-blind ones. Which brings us back to those who wring their hands over Richard Spencer getting punched.
What we now call the Holocaust was already rolling in 1938, despite the fact the term “Final Solution” was still three years away. The Nuremberg Laws had been in place for three years and Dachau had been in operation for five years and was already taking Jewish inmates. The denialists in the British Tory Party, in the America First Movement, and within Germany’s conservative establishment were just too blinded by the glare of their own privilege and their own casual or not-so-casual racism to see what was out in the open.