Why was appeasement a disaster?

Appeasement was a disaster primarily because it allowed aggressive powers, particularly Nazi Germany, to expand unchecked, emboldening their expansionist ambitions. By conceding to Hitler’s demands, such as in the Munich Agreement of 1938, Western democracies underestimated the threat he posed, ultimately leading to World War II. This strategy failed to prevent conflict and instead demonstrated that aggression would not be met with resistance, resulting in catastrophic consequences for Europe and beyond.