The Winter War between Finland and the USSR was incredibly brutal. I think Finland lost 20 to 25% of their population but the Soviets walked into a nightmare.
It was Stalin’s fault for either murdering and sending all of his officers to the gulag before the war.
By January, things were not going good for Ivan; particularly at Suomussalmi and Ratte and Kollaa's *Killer Hill*- where Simo Häyhä fought.
The Finnish butcher's bill was pretty close to 27,000 lost, plus around 50,000 seriously wounded and out of action until the war's end in February 1940- as was Simo Häyhä.
But the Russian casualties were certainly MUCH higher than the *official line* propaganda reports. And years later, when Nikita Kruschev was the Soviet Premier, he looked back on his days as a pmilitary commisar with troops during the Finnish *exercise* and remarked that the loss of a million men had not been worth it.
In 1959, after more successful adventures in East Germany and Budapest, the Soviets considered visiting Finland again; the prospect of some nice Baltic ports was just too attractive. The Finns had no great defense budget, no massive standing army or conscript pool, and knew that if another invasion came, they were not in a good p[oistion to do much about it.
They opened their national armories full of equipment left over from the 1918 Civil War and the 1939 Talvisota to U.S. arms merchant Sam Cummings of Interarmco. Cummings piched the most collectable and interesting specimens, and in turn the Finns received 300,000 former British Sten guns letover from WWII. The Finnish industrial base began churning out Sten magazines and 9mm SMG ammo, and for some reason the Soviets, with long memories of the crop of the Red Army wounded and freezing to death in the -40 degrees temperatures in the Finnish forests, and decided not to come a calling again.
The Red flag of the Soviet Union no longer flies, save over a few student unions in the USA. That of free Finland still does.