World War II

Story hook

At 05:30 on 1 September 1939, the German pocket battleship Schleswig-Holstein opened fire on the Polish military depot at Westerplatte, Danzig. By midday, the Wehrmacht had crossed the Polish frontier on a 1,500-km front. Two days later, on 3 September, Britain and France honored their guarantees to Poland and declared war on Germany. The Second World War had begun.

Six years and one day later, on 2 September 1945, the Japanese delegation signed the Instrument of Surrender on the deck of USS Missouri in Tokyo Bay. Between Westerplatte and Tokyo Bay lay the deadliest conflict in human history: an estimated 70-85 million dead (3% of the 1940 world population), the Holocaust (6 million Jews + 5 million others systematically murdered), the first and only military use of nuclear weapons (Hiroshima 6 August + Nagasaki 9 August 1945), the redrawing of the world map, and a new institution called the United Nations founded 24 October 1945 in San Francisco.

Even more consequentially, WWII produced the conditions for Indian independence in 1947 (the British exchequer was emptied; Attlee's Labour government could no longer afford the Raj), the partition of Korea (1945) and Germany (1949), the rise of the United States and Soviet Union as the two superpowers, and the Cold War order that defined the next four decades.

Why this matters for UPSC

World War II is a near-certain Mains GS-I/II topic every year — questions on causes, theatre-by-theatre, UN formation, India's role, post-war settlement. Prelims tests dates (1939-45), operations (Barbarossa, Overlord, Midway), conferences (Tehran, Yalta, Potsdam), and key personalities. For Interview, the post-1945 order, decolonisation impact, and India's UN role are favorites.