Editing 1940 (section)

===December===
{{Main|December 1940}}
*[[December]] – [[Timely Comics]]' [[Captain America|Captain America Comics]] #1 (cover dated March 1941), [[first appearance]] of [[Captain America]] and [[Bucky Barnes|Bucky]], hits newsstands in the United States.
*[[December 1]] – [[Manuel Ávila Camacho]] takes office as [[President of Mexico]].
*[[December 6]] – British submarine {{HMS|Regulus|N88|6}} is sunk near [[Taranto]].
*[[December 8]] – The [[Chicago Bears]], in what will become the most one-sided victory in [[National Football League]] history, defeat the [[Washington Redskins]] 73–0 in the 1940 NFL Championship Game.
*[[December 9]] – WWII: [[Operation Compass]] – British forces in North Africa begin their first major offensive, with an attack on Italian forces at [[Sidi Barrani]], [[Egypt]].
*[[December 12]] and [[December 15]] – WWII: [[Sheffield Blitz]] ("Operation Crucible") – The [[Yorkshire]] steelmaking city of [[Sheffield]] in England is badly damaged by German air-raids.
*[[December 14]] – WWII:
**British destroyers {{HMS|Hereward|H93|6}} and {{HMS|Hyperion|H97|6}} sink an Italian submarine off [[Bardia]].
**Royal Navy [[Fairey Swordfish]] based on [[Malta]] bomb [[Tripoli, Libya|Tripoli]].
**[[Plutonium]] is first synthesized in the laboratory, by a team led by [[Glenn T. Seaborg]] and [[Edwin McMillan]], at the [[University of California, Berkeley]].
*[[December 16]] – WWII: [[Operation Abigail Rachel]] – The [[Royal Air Force|RAF]] bombs [[Mannheim]].
*[[December 17]] – President Roosevelt, at his regular press conference, first sets forth the outline of his plan to send aid to Great Britain, which will become known as [[Lend-Lease]].
*[[December 23]] – WWII: [[Winston Churchill]], in a broadcast address to the people of Italy, blames [[Benito Mussolini]] for leading his nation to war against the British, contrary to Italy's historic friendship with them: "One man has arrayed the trustees and inheritors of ancient Rome upon the side of the ferocious pagan barbarians."
*[[December 24]] – [[Mahatma Gandhi]], Indian spiritual non-violence leader, writes his second letter to [[Adolf Hitler]], addressing him as "My friend", and requesting him to stop the war Germany had begun.
*[[December 25]] – The German cruiser ''[[German cruiser Admiral Hipper|Admiral Hipper]]'' attacks a British shipping convoy (WS 5A) en route to [[Sierra Leone]] 700 miles (1,100&nbsp;km) west of [[Cape Finisterre]] in [[Spain]]. ''Admiral Hipper'' sinks one ship but has to withdraw with engine trouble.
*[[December 27]] – WWII: German auxiliary cruiser ''[[German auxiliary cruiser Komet|Komet]]'' shells and heavily damages the phosphate production facilities on the Pacific island of [[Nauru]] (under Australian protection at this time) while flying the Japanese flag. The bombardment lasts an hour and causes the loss of 13,000 tons of oil.
*[[December 29]]
**[[Franklin D. Roosevelt]], in a [[fireside chat]] to the nation, declares that the United States must become "the great arsenal of democracy."
**WWII: "[[Second Great Fire of London]]" – The [[Luftwaffe]] carries out a massive incendiary bombing raid, starting 1,500 fires. Many famous buildings, including the [[Guildhall, London|Guildhall]] and Trinity House, are either damaged or destroyed.