Seventy-five years ago this week, shortly after the start of World War II, tiny Finland began a valiant, 105-day stand against a massive Soviet invasion that became the stuff of modern military legend.

Innately tough, dedicated to their country and their brilliant commander-in-chief, Gustaf Mannerheim, and using one of the most brutal winters in history to their advantage, the Finns exacted a terrible toll on the Red Army before their southern defenses finally were breached and they were forced to the peace table in March 1940.

Historian John Suprin of the U.S. Army Command and General Staff College at Fort Leavenworth examines the lead-up to the hostilities, the fighting that left more than 126,000 Soviet troops killed or missing, and the war’s ramifications.