Appeasemet: To yield or concede to the belligerent demands of (a nation, group, person, etc.) in a conciliatory effort, sometimes at the expense of justice or other principles.
Britain's leader, Neville Chamberlain, thought the Treaty of Versailles was too harsh on the German people. Britain, France, Germany and Italy signed The Munich Agreement which gave the Sudetenland to Germany. Hitler was not satisfied with stopping there and went on to invade other countries. Chamberlain promised Poland it would help them in case of a German invasion. When this happened it became obvious that the policy of appeasement had failed.