Video: 'Soviets invade Finland'

(Thursday, November 30, 1939, 6:50 a.m. Eastern European Time; during the Winter War, part of World War II) — The Winter War began this morning as Soviet troops crossed the border on the Karelian Isthmus after a half-hour artillery bombardment.

Soviet airplanes began dropping bombs on Helsinki at approximately 9:00 a.m.

Video: 'BBC Documentary - The Winter War of Finland and Russia' (Nov. 30, 1939, at 5:14)

21 Soviet divisions, totaling 450,000 men, participated in the invasion, which began three months after the outbreak of World War II, inflicting substantial damage and casualties.

Video: 'The World At War 1973(World War II Documentary) 02.Distant War (September 1939 – May 1940)' (Nov. 30, 1939, at 27:32)

According to the terms of the Molotov–Ribbentrop Pact of Aug. 23, 1939, Germany had given the Soviet Union carte blanche to do as it wished regarding Finland.