WHAT HAPPENED IN 1941.
Look what happened the 1941.

World War II: Emperor Hirohito of Japan gives the final approval to initiate war against the United States. (1. December 1941)

World War II: Fiorello La Guardia, Mayor of New York City and Director of the Office of Civilian Defense, signs Administrative Order 9, creating the Civil Air Patrol. (1. December 1941)

World War II: In the Battle of Moscow, Georgy Zhukov launches a massive Soviet counter-attack against the German army, with the biggest offensive launched against Army Group Centre. (5. December 1941)

World War II: Great Britain declares war on Finland, Hungary and Romania. (5. December 1941)

World War II: The United Kingdom and Canada declare war on Finland in support of the Soviet Union during the Continuation War. (6. December 1941)

World War II: Attack on Pearl Harbor – The Imperial Japanese Navy carries out a surprise attack on the United States Pacific Fleet and its defending Army and Marine air forces at Pearl Harbor, Hawaii. (For Japan's near-simultaneous attacks on Eastern Hemisphere targets, see December 8.) (7. December 1941)

World War II: U.S. President Franklin D. Roosevelt declares December 7 to be "a date which will live in infamy", after which the U.S. declares war on Japan. (8. December 1941)

World War II: Japanese forces simultaneously invade Malaya, Thailand, Hong Kong, the Philippines, and the Dutch East Indies. (See December 7 for the concurrent attack on Pearl Harbor in the Western Hemisphere.) (8. December 1941)

World War II: The Republic of China, Cuba, Guatemala, and the Philippine Commonwealth, declare war on Germany and Japan. (9. December 1941)

World War II: The American 19th Bombardment Group attacks Japanese ships off the coast of Vigan, Luzon. (9. December 1941)

World War II: The Royal Navy capital ships HMS Prince of Wales and HMS Repulse are sunk by Imperial Japanese Navy torpedo bombers near Malaya. (10. December 1941)

World War II: Battle of the Philippines – Imperial Japanese forces under the command of General Masaharu Homma land on the Philippine mainland. (10. December 1941)

World War II: Germany and Italy declare war on the United States, following the Americans' declaration of war on the Empire of Japan in the wake of the attack on Pearl Harbor. The United States, in turn, declares war on them. (11. December 1941)

World War II: Poland declares war on the Empire of Japan. (11. December 1941)

World War II: Fifty-four Japanese A6M Zero fighters raid Batangas Field, Philippines. Jesús Villamor and four Filipino fighter pilots fend them off; César Basa is killed. (12. December 1941)

World War II: USMC F4F "Wildcats" sink the first 4 major Japanese ships off Wake Island. (12. December 1941)

World War II: The United Kingdom declares war on Bulgaria. Hungary and Romania declare war on the United States. India declares war on Japan. (12. December 1941)

Adolf Hitler declares the imminent extermination of the Jews at a meeting in the Reich Chancellery (12. December 1941)

World War II: The Kingdom of Hungary and Kingdom of Romania declare war on the United States. (13. December 1941)

World War II: Japan signs a treaty of alliance with Thailand. (14. December 1941)