Definition
Appeasement is the policy of granting concessions to an aggressive power in order to avoid conflict. The term is most strongly associated with the response of Britain and France to Nazi Germany during the 1930s, as Hitler steadily violated the post-war settlement.
The defining episode was the Munich Agreement of 1938, in which Britain and France permitted Germany to annex the Sudetenland region of Czechoslovakia. British Prime Minister Neville Chamberlain returned claiming he had secured peace, but Germany invaded the rest of Czechoslovakia within months.
Why it matters
How it works
Appeasement assumes that an aggressor has finite, reasonable goals that can be satisfied. The appeasing power calculates that a manageable concession is cheaper than war, especially when its own military and public are unprepared for conflict.
The strategy fails when the aggressor's aims are in fact unlimited. Concessions then signal weakness and embolden further demands. After Munich, Britain and France abandoned appeasement and pledged to defend Poland, leading to war when Germany invaded in 1939.