Appeasement
The 1930s policy of conceding to Hitler's demands to avoid war, discredited at Munich in 1938 and now shorthand for weakness that invites aggression.

Appeasement is the policy, forever fixed to the 1930s, of granting an aggressive power's demands in the hope that each concession will be the last. The word once meant merely the pursuit of peace; the Munich crisis of 1938 turned it into a synonym for weakness dressed up as prudence. British prime minister Neville Chamberlain and French premier Édouard Daladier, desperate to avoid a rerun of the First World War's slaughter, chose to buy Adolf Hitler off rather than fight him. The bargain bought one year, and it taught Hitler that the democracies would not.
Munich, 1938
Munich was the climax of a pattern. Hitler had already torn up the Versailles limits by rearming, remilitarized the Rhineland in 1936, and swallowed Austria in the Anschluss of March 1938, each move drawing protest but no resistance. His target that autumn was the Sudetenland, the German-speaking rim of Czechoslovakia, a functioning democracy allied to France and shielded by strong mountain fortifications. Posing as the protector of oppressed Germans, Hitler threatened war. On the night of 29-30 September 1938 the leaders of Germany, Britain, France, and Italy met in Munich and signed the Sudetenland over to the Reich. Czechoslovakia, whose fate was being decided, was not invited; it was simply handed the terms. Stripped of its border defenses, the country was left open to invasion. Chamberlain flew home to Heston Aerodrome and waved a second sheet he and Hitler had signed; that evening, from a window at 10 Downing Street, he told a cheering crowd he believed it meant 'peace for our time.' Winston Churchill, nearly alone in the Commons, called it 'a total and unmitigated defeat.'
Why it failed
The whole gamble rested on a reading of Hitler as a nationalist with limited aims: gather the ethnic Germans into the Reich, then stop. The reading was wrong. In March 1939 German troops marched into Prague and seized the rest of Czechoslovakia, a land with no German majority to 'liberate,' exposing the Sudeten grievance as a pretext all along. British opinion turned overnight. Chamberlain guaranteed Poland, and when Germany invaded on 1 September 1939, Britain and France declared war. Appeasement had not prevented the world war; it had postponed it by a year, on terms that let Germany grow stronger and handed Berlin the Czech army's divisions and the Skoda works, one of Europe's great arms manufacturers. There was a further cost: the Soviet Union, pointedly excluded from Munich, drew the lesson that the West would not fight, and within a year signed the pact with Hitler that cleared his path into Poland.
Context and verdict
The men of Munich were neither fools nor traitors, and the case for them is real. Britain was militarily unready, its Dominions reluctant, its public still haunted by the Somme; radar and the Spitfire were only just coming online, and almost any price looked worth paying to avoid another 1914. Yet history's judgment is harsh, because the concessions were made from weakness to a leader whose appetite grew with the eating, and they signaled that aggression paid.
The deepest legacy is the 'Munich analogy,' the reflex to brand every diplomatic concession as appeasement and every adversary as a new Hitler. It has been invoked to justify hard lines at Suez in 1956, in Vietnam, and before the 2003 invasion of Iraq, often stretched well past the point of usefulness. The real lesson of 1938 is narrower and harder: concessions to a genuinely unlimited aggressor do not buy peace, they only raise the price of the war that follows.