The correct answer is "Adolf Hitler would only go on to take more land, leading to the start of WW2."
The way in which Neville Chamberlain's policy was a failure concerning Hitler was "Adolf Hitler would only go on to take more land, leading to the start of WW2."
Neville Chamberlain was the British Prime Minister before the beginning of World War II. He decided that the best foreign policy for Adolph Hitler and Germany was the policy of Appeasement, just to try to keep Hitler under control. Chamberlain, with the support of France, let Hitler expand German territories because they did not want another European war after the pain, suffering, and destruction left by World War I.
The police of appeasement failed. Hitler's troops invaded Poland on September 1, 1939, and this represented the beginning of World War II.