How long did World War II last?

World War II lasted for approximately six years, spanning from 1939 to 1945. This extended duration can be attributed to a multitude of factors. The conflict began in September 1939 when Germany invaded Poland, triggering a series of events and alliances that escalated into a global conflict. It involved numerous countries across several continents, each engaging in fierce battles and strategic warfare. The war continued for several years due to the scale of the conflict, the immense military resources deployed, and the resilience and determination demonstrated by the opposing powers. Additionally, the complexity of the geopolitical landscape, various theaters of war, and the strategic movements and counter-movements of forces all contributed to the extended duration of World War II.