Why did the invasion of Poland launch World War II? Violated Hitler’s nonaggression pact with stolen. It led Britain and France to abandon the policy of appeasement. It led the United States to abandon the policy of neutrality. It was the first time German forces used the blitzkrieg strategy.

The correct answer is "It violated Hitler’s nonaggression pact with Stalin." The invasion of Poland by Germany in September 1939 marked the violation of the Molotov-Ribbentrop Pact, also known as the Hitler-Stalin Pact. This agreement between Nazi Germany and the Soviet Union included a nonaggression clause, in which both countries agreed not to attack each other. However, the invasion of Poland by Germany demonstrated Hitler's willingness to break this pact and disregard agreements with other countries. This event eventually led to Britain and France abandoning their policy of appeasement towards Germany and declaring war, thus launching World War II. The invasion of Poland did not directly lead to the United States abandoning its policy of neutrality, nor was it the first time German forces used the blitzkrieg strategy.