Final answer:
After Germany's annexation of the Sudetenland post-1938, the appeasement policy failed as Germany further occupied Czechoslovakia and expanded its territory. The Munich Conference embodied appeasement, and subsequent events led to World War II. Western powers incorrectly believed appeasement would quell Hitler's ambitions, only realizing too late that war was unavoidable.
Step-by-step explanation:
Post-1938, after Germany's demands for concessions from Czechoslovakia led to the Munich Agreement, the situation in Europe deteriorated rapidly. The annexation of the Sudetenland was followed by Germany's occupation of the remaining Czech territories, defying the settlement at Munich. Then Poland and Hungary divided up parts of Czechoslovakia amongst themselves. By spring, Germany expanded further by annexing Memel from Lithuania, and Italy invaded and took control of Albania. This demonstrated that the appeasement policy was ineffective, leading to a loss of faith in peace efforts and setting the stage for World War II.
Additionally, the Munich Conference exemplified the policy of appeasement as Britain and France, along with Italy, allowed Germany to annex parts of Czechoslovakia. The Western powers hoped this would satisfy Hitler's expansionist aims and prevent war, but it was in vain. Winston Churchill famously criticised the appeasement strategy, asserting that 'They had to choose between war and dishonor. They chose dishonor; they will have war.'
The occupation of Czechoslovakia fueled debates within Western countries about the greater threat - Nazi Germany or the Soviet Union. While some hoped for a German alliance against the Soviets, the ultimate realization that Hitler was not to be appeased culminated in the inevitable march towards global conflict.