Q: Why on earth did Chamberlain's policy change from 1938 to 1939?

Chamberlain changed his policy from appeasement in early 1938 to fighting a war by 1939. During the time, many events happened in Europe and England. Hitler was expending his power, which didn't allow Chamberlain to continue his appeasement. This drove many people in England against Chamberlain's idea. The expending of fascist and the objection of his own country cut down the policy of appeasement. Chamberlain had to drop his idea and prepare for the war. Events in …

…was still working for the war. And finally when Hitler invaded Poland on Sep 1, 1939, Britain declared war on Germany 2 days later and stopped the whole year's preparing for war. The fact from 1938 to 1939 showed that the appeasement Chamberlain supported was useless. It could neither stop the expending of fascist nor create a peace world. No one trusted or supported it. Furthermore, it may have pushed Britain into danger. Therefore, Chamberlain changed his policy from 1938 to 1939.