@Wolfshanze:
That’s all that needs to be said right there and is spot-on. Chamberlain sold-out the Czechs, who weren’t even invited to the discussion.
Among the many lies Woodrow Wilson told, one was his claim that the Entente was fighting for self-determination. That idea was of course abandoned at Versailles, as was every other lofty promise Wilson had made.
The people in the Sudetenland were German, and wanted to be part of Germany. The Czech government had been treating them like second-class citizens, with an apparent long-term plan of replacing them with Czechs. (After WWII the Sudetenland was ethnically cleansed of Germans, thus fulfilling the apparent long-term plan.)
In January 1938, millions of Sudeten Germans were under hostile Czech occupation. By the end of the year millions of Czechs were under hostile German occupation. Neither situation was consistent with self-determination. But the British government had not supported self-determination as a value at Versailles or at any point after WWI, making it difficult for them to convincingly argue the latter situation was worse than the former.
At Versailles, one of the reasons for giving Germany’s neighbors land which rightfully belonged to Germany was to ensure that there would always be a significant bone of contention between Germany and her immediate neighbors. This would cause diplomatic isolation for Germany. The strategy worked. In 1935 the Czech government signed a defensive alliance with the Soviet Union. That alliance created fear within Germany: fear of what could happen if the Soviets invaded Germany with soldiers stationed on Czech soil. The Versailles policy of giving German land to Germany’s neighbors also drove a wedge between Germany and Poland; with the latter nation embracing an ill-conceived, disastrous alliance with Britain and France as an alternative to restoring West Prussia to German control.
Starting apparently in 1938, Germany had adopted a carrot and stick policy towards those nations east of itself, west of the Soviet Union. Any nation in that region which adopted an anti-German foreign policy would typically be annexed. Whereas, Germany would extend favorable treatment to those Eastern European nations which embraced pro-German, anti-Soviet foreign policies. That strategy paid off. By the time Germany launched Operation Barbarossa, every nation in Eastern Europe was either an ally of Germany (such as Romania), was neutral in Germany’s favor, or was under German occupation. (Except of course for those Eastern European nations under Soviet occupation.)