How did appeasement impact Europe and the US in WWII?

Appeasement in the lead-up to World War II, particularly by Britain and France towards Nazi Germany, allowed Hitler to expand aggressively without facing immediate consequences, emboldening him to pursue further territorial ambitions. This policy ultimately failed, leading to the invasion of Poland in 1939 and the outbreak of the war. In the U.S., the initial stance of neutrality and isolationism was challenged as the threat of global conflict grew, prompting a shift towards greater involvement in European affairs. The consequences of appeasement underscored the dangers of inaction against aggression, shaping international relations for decades to come.