December 6
Politics, Italy
Marshal Pietro Badoglio, Italy's commander-in-chief, resigns.

British, Indian and Australian troops in Egypt

December 9-11
Africa, Egypt
General Sir Archibald Wavell, the commander-in-chief in the Middle East and North Africa, launches the first British offensive in the Western Desert. Major General Sir Richard O'Connor's Western Desert Force of 31,000 British and Commonwealth troops, supported by aircraft and long-range naval gunfire, is ordered to attack the fortified camps that have been established by the Italians in Egypt. Sidi Barrani is captured on the 10th and 34,000 Italians are taken prisoner as they retreat rapidly from Egypt. It is a famous victory in the face of overwhelming odds.

December 18
Politics, Germany
Adolf Hitler issues his plan for invading the Soviet Union, code-named Operation Barbarossa. His Directive No. 21 retains a three-pronged offensive but the weight of the invasion plan has now shifted northward to Lenin-grad and the Baltic area, where Army Groups North and Center are to annihilate the enemy forces, before attacking and occupying Moscow.

December 29
Politics, United States
In President Franklin D. Roosevelt's 'fireside chat' broadcast, he describes how the United States must become the 'arsenal of democracy' by giving maximum assistance to Britain in its fight against the Axis powers.