A leader waved a signed paper and promised 'peace for our time'; war came within a year
In September 1938, Britain, France, Germany, and Italy met in Munich and agreed to let Hitler annex Czechoslovakia's Sudetenland, whose own government wasn't even invited, in exchange for his promise to seek no further territory. British PM Neville Chamberlain returned home declaring he'd secured 'peace for our time.' Germany occupied the rest of Czechoslovakia within six months and invaded Poland within a year, and 'Munich' became lasting shorthand for the danger of appeasing an aggressor.