A crucial prelude to Operation Barbarossa and the war on the Eastern Front of World War II: the Winter War between the USSR and Finland. 

Spoiler alert: The Soviet Union gets its ass kicked by a force less than half the size.

This episode is the first part in a three-part series on the Winter War; parts 2 and 3 will be for supporters and members only. 

Map 1: The Mannerheim Line of Finnish defences across the Karelian Isthmus.

Map 2: The USSR's four main attacks on Finland, 30 November 1939 

Map 3: Soviet advances in the Karelian Isthmus, December 1939

Map 4: Ladogo Karelia, north of Lake Ladoga

Sources:

Philip Jowett and Brent Snodgrass, Finland at War 1939–45. New York, NY: Osprey Publishing, 2006.

Wikipedia: Timeline of World War II (1939)

—: The Winter War

The Winter War. Captivating History, 2020.

Vesa Nenye, Peter Munter, Toni Wirtanen and Chris Birks, Finland at War: The Winter War, 1939–40. New York, NY: Osprey Publishing, 2018.

Sound effects obtained from Zapsplat.