Border disputes between Ecuador and Peru erupted into full scale war. Who started full scale combat is disputed, but the war generally went Peru's way during the month long fighting.
Ecuador was very outmatched in the fighting and has always maintained that it was invaded by Peru, which Peru has always denied. At any rate, Peru's military was much more advanced than Ecuador's and this showed in the short war.
In 1942 Ecuador declared war on Japan, but not Germany, in order to improve its international position and in order to receive American military material support, which it did receive. Peru declared war on the Axis powers in 1945.
The countries would fight two more border wars in the 20th Century.
This war was the first South American war to feature paratroopers, which Peru used in the war.
The Battle of Damour commenced in Lebanon. Damour was the French seat of government in Lebanon and is located to the south of Beirut. The battle was fought principally by Australians on the British side.
On the same day, Auchinleck assumed his duties as the British Commander in Chief in the Middle East.
Auchinleck would be initially successful but would prove to be one of several British commanders in the Middle East who was unable to bring about a British victory. He achieved early success against the Africa Korps after being assigned as CoC in the Middle East, but then suffered setbacks that Churchill felt merited a replacement.
Auchinleck had a major role in preparing the British Empire in that he modernized the Indian Army between the wars. During that time, he met and married American Jessie Stewart who was regarded as a great beauty. She was 16 years his junior.
Jessie would in turn have an odd role in the British command during the war in that she commenced an affair with Auchinleck's friend, RAF commander Sir Richard Peirse. The affair caused Peirce to be regarded as neglecting his duties and caused him to be recalled to the UK, with Mrs. Auchinleck going with him. Peirse would be accordingly retired during the war, his career ending in a type of disgrace during the war itself. Auchinleck never recovered from the divorce and carried Jesse's photograph in his wallet for the rest of his life, That he genuinely adored Jesse is clear, and that the divorce also changed him is clear, but there remains a scholarly debate on whether Auchinleck himself my have had homosexual inclinations. His biographer maintains that these rumors are false, but another writer asserts the opposite, citing "moral aversion" for Montgomery's inability to get along with him.
And as detailed here, German U-boats began patrolling in the Arctic.