The Outbreak of World War II: Key Events of 1939

1939: War in Europe

The Invasion of Poland
The war in Europe began on September 1, 1939, when Germany invaded Poland. Hitler's intentions were to capture the city of Danzig (where both Germans and Poles lived) and to dominate the urban corridor linking to Germany. In front of the international community, the border conflict was used as a pretext for the invasion. On September 3, the United Kingdom and France declared war on Germany. Although the United States established a sea blockade, it did not invade Germany, and London and Paris did not show solid enthusiasm. France moved slowly and carried out minor attacks on a small scale. Poland was not sent any significant help.

Meanwhile, in Poland, the German Blitzkrieg or Lightning War was executed. In this military strategy, the German Army bombed key targets, especially in surprise attacks on military convoys. The Polish army, dispersed throughout the territory without a unified command, gradually gave up. Warsaw fell on September 27, and the last Polish troops surrendered on October 6.

On September 17, Germany and the Soviet Union signed the Ribbentrop Pact, allowing the Soviet Union to attack eastern Poland. This opened a second front, leading to the collapse of Polish defenses. The next day, the Polish president and military commander fled the country. However, Poland was not officially surrendered. Neighboring countries provided refuge for the army, and strong resistance was established within Poland.

Then, in 1939 and 1940, German armies would meet in the winter, while France and the United States did not launch any attacks. Some journalists referred to this period as the "Phoney War" or "Sitzkrieg" due to the lack of significant military action.

Winter
In winter, on November 30, 1939, the Soviet Union attacked Finland. The Soviet Army was outnumbered by Finland's forces, but the Red Army struggled to make progress. Finnish defenses successfully prevented the invasion, ultimately defeating the Soviets in Finland and the strategic area around Leningrad. However, this raised questions about the Red Army's capabilities in Europe among many in the Chancellery in Berlin.

Under the Molotov-Ribbentrop Pact, the Soviet Union occupied Estonia, Latvia, and Lithuania in June 1940, as well as the Northern Bukovina region of Bessarabia.