History of Warfare Summary 11 - World War II Part 1: The Invasion of Poland and the Start of the War

On September 1, 1939, Germany invaded Poland. The German army rapidly broke through Polish defenses, heavily utilizing tanks and aircraft. The Soviet Union also entered Poland from the east on September 17. Poland found itself isolated, attacked from both Germany and the Soviet Union. Britain and France demanded Germany withdraw, but when their demand was rejected, they declared war on Germany on September 3. This marked the full-scale beginning of World War II in Europe. The Polish army resisted until the very end, but it was difficult to fend off simultaneous attacks from Germany and the Soviet Union. With the fall of Warsaw at the end of September, Poland's organized resistance effectively ceased. Subsequently, Germany and the Soviet Union divided and occupied Polish territory. Although Britain and France had declared war on Germany, no large-scale ground battles occurred on the Western Front for some time. This period was known as the Phoney War. However, Europe as a whole had already entered a prolonged conflict.