Yet they still pushed through the atrocious, worthless Munich agreement that so completely eviscerated Czechoslovakia, despite knowing not only that the Nazi war machine had no realistic hope of major conquest against fully intact Czech territory, but also that the High command of the Wehrmacht itself was near mutiny at the idea of trying such a thing. Had Chamberlain simply shown more spine at that point, there very likely never would have been a genocidal Nazi conquest of Europe. I know that the what-ifs of history are full of unknown unknowns but given what did happen, It's hard to imagine a rejection of German demands in 1938 possibly having lead to as bad, let alone worse..
Probably he wanted to be in good terms with Hitler and get it closer to attack the USSR. Chamberlain had a very antisoviet stance (even in contrast with other cabinet members) and maybe he reasonably thought Hitler would not overextend by also opening a west front. In that line of reason, having Hitler in the government and not disturb it with a coup was a positive for him.
