Giving in to the demands of aggressive powers to avoid war, as long as those demands appear reasonable. Such a policy was pursued by Britain and France in dealing with Germany in the latter half of the 1930s.
Policy adopted by major Western political powers towards Adolf Hitler's ambitions in the Munich Agreement of 1938. Leaders, famously including Britain's Neville Chamberlain, agreed to allow Hitler portions of land in Eastern Europe in order to avoid war.
The policy of gratifying one's enemy with concession and special grants by sacrificing even principles.