Hitler was Austrian and the majority of the Austrians wanted to be in Nazis Germany and there was very little opposition to him taking Austria because the Austrians wanted the Anschluss to happen expect the Hapsburg royal family of the former Austrian empire. The sudetenland Germans were actually treated not too good in Bohemia so that how he justified it to the western allies to take it.
Explanation:
The main reason is that the allies didn't want war again
