Roughly the same as the eastern theater during WW2 which the Russians triumphed in the end.
At that time the Soviet Union was allied with the West. It isn't these days. And even then:
en.m.wikipedia.org/wiki/Winter_War
"
Despite superior military strength, especially in tanks and aircraft,
the Soviet Union suffered severe losses and initially made little headway. The League of Nations
deemed the attack illegal and expelled the Soviet Union from the organisation."
This fragment sounds familiar too, doesn't it?:
"The Soviets made several demands, including that Finland cede substantial border territories in exchange for land elsewhere,
claiming security reasons-primarily the protection of Leningrad, 32 km (20 mi) from the Finnish border. When Finland refused, the Soviets invaded. Most sources conclude that
the Soviet Union had intended to conquer all of Finland, and use the establishment of the puppet Finnish Communist government"
it is their holy war for independence.
Exactly, it's Ukrainians'
otechestvennaya voyna. And since Ukrainians stopped at the Russian border Putin can't claim the same.