The Invasion of Poland Wasn't Hitler's First Aggression. Here's Why That Move Marked the Beginning of WWII

Thus began World War II, and this weekend Vice President Mike Pence will travel to Poland to mark the anniversary of that event.But the invasion of Poland wasn’t the first time German forces had been put to work for Hitler’s goal of European domination. “When Hitler invades Poland in ’39 there is no political support any longer for appeasement,” explains Rob Citino, Senior Historian at The National WWII Museum.Though France urged Britain to wait, says Tim Bouverie, author of Appeasement: Chamberlain, Hitler, Churchill, and the Road to War, many British politicians feared the implications of not keeping the promise to Poland, and they were done giving Hitler the benefit of the doubt.“Hitler had proven, by tearing up the Munich agreement and invading Czechoslovakia in March of that year, that he could not be trusted and that he had to be stopped,” Bouverie says. By falsely claiming that he only wanted to fix damage done to Germany from World War I and restore German lands to German people, Hitler had previously been able to convince his counterparts—already wary of war—to hold off. 17, the Soviet Union also invaded Poland, in accord with a non-aggression agreement Hitler and Stalin had come to that summer; that agreement would end on June 22, 1941, when the Nazis invaded Soviet territory.)“It seems Hitler can no longer be appeased [in 1939], but attempting to appease him was wrong all along,” Citino says.