That strategy reached its apex when the three parties signed the Munich Agreement on Sept. Previously, however, the other European powers had pursued a strategy of appeasement, giving Hitler what they deemed reasonable concessions, in order to avoid all-out war. Thus began World War II, and this weekend Vice President Mike Pence will travel to Poland to mark the anniversary of that event.īut the invasion of Poland wasn’t the first time German forces had been put to work for Hitler’s goal of European domination. 3, 1939, Britain and France declared war. Hitler ignored the demand, and two days later, on Sept. 1, 1939, the British gave Nazi dictator Adolf Hitler an ultimatum: pull out of Poland, or else. After roughly 1.5 million German soldiers, more than 2,000 airplanes and more than 2,500 tanks crossed the Polish border on Sept.