September 22, 1940 – September 26, 1940
Japanese forces attack Lạng Sơn and land near Haiphong, compelling the French administration to accept Japanese bases in Tonkin.
Nationalist leader Phan Bội Châu dies in Huế after years under French house arrest.
Soviet and Mongolian forces under Georgy Zhukov defeat the Japanese on the Mongolian–Manchurian border.
Germany invades Poland, starting the deadliest conflict in human history, which ends with Japan's formal surrender on 2 September 1945.
Nazi Germany and its collaborators systematically murder some six million European Jews, along with millions of other victims.
At Pác Bó, Hồ Chí Minh presides over the founding of the League for the Independence of Vietnam (Việt Minh).
The Imperial Japanese Navy launches a surprise attack on the US naval base at Pearl Harbor, Hawaii, bringing the United States into World War II.