Furthermore, Polish troops were too thinly spread across the Polish-German border, meaning that the Wehrmacht easily broke through their defenses.
On September 1, 1939, Nazi Germany invaded Poland, marking the beginning of the Second World War, as France and the United Kingdom (UK) declared war on Germany shortly afterward. While the Polish army was about the same size as the German army on paper, poor supplies and technology made them no match for the German Blitzkrieg. Furthermore, Polish troops were too thinly spread across the Polish-German border, meaning that the Wehrmacht easily broke through their defenses. Then, on September 17, the Soviet Union (USSR) also invaded. Despite being ideological enemies (and "racial" enemies according to the Nazis), the USSR and Germany signed a non-aggression pact the previous month to facilitate the would-be partition of Poland. Thus, by early October 1939, the German and Soviet invasion was complete, with the Nazis occupying the west of the country and the Soviets occupying the east.