The Winter War is a somewhat obscure skirmish initiated by Stalin against Finland in late 1939. It was soon eclipsed by a larger conflict that would occupy much of the world’s attention for the next several years. But, to the Finnish people, the Winter War was kind of a big deal. Since this conflict is noted in a prior post, it might be worthwhile to provide a few particulars.
In late August of ’39 the USSR and Germany signed a “non-aggression” treaty known as the Molotov-Ribbentrop Pact. This agreement set terms for mutual security covering a ten-year period with an option for a five-year extension. The Pact’s lesser-known feature consisted of secret protocols that divided central and northern Europe into “spheres of influence”.
In other words, Stalin and Hitler negotiated who-would-get-what before the first shot was fired in World War II. By the way, that shot occurred in Poland only one week later. Irony of ironies, the non-aggression treaty lasted all of 22 months. In June 1941, Germany invaded the Soviet Union in Operation Barbarossa. But, now we are getting slightly ahead of the story.

With the security pact in hand, Stalin turned his attention to consolidating the USSR’s secretly negotiated gains. Finland was in the Soviet bucket along with Estonia, Latvia, Lithuania and eastern Poland. Conveniently, the Soviets considered Finland a serious threat to national security, ostensibly due to Leningrad’s (Saint Petersburg) close proximity to the Finnish border – about 20 miles away (32km).

So, on 30 November 1939, the USSR invaded a country 2% its size by population. But what was expected to be a quick run to Helsinki (250mi/400km from Leningrad) soon became a stalemate. It turns out the Finnish people are very adept with skis and winter survival skills. And the Red Army was not so committed to the mission. Opposition forces cloaked in white camo made clever hit-and-run attacks as Soviet forces struggled to gain traction, literally and figuratively. Three months later Stalin gave up. He had other fish to fry. But he did manage to seize territory.

Of course, the story of the Winter War – no matter how brief – cannot be told without also offering a quick summary of the Continuation War (1941-44).
As the USSR busied itself defending Mother Russia against Operation Barbarossa, Finland (with German assistance) endeavored to reclaim territory lost in the Winter War. This effort was initially successful. However, as Germany’s war prospects began to dim so, too, did Finland’s ability to maintain control of the regained ground.
The Continuation War ended by way of armistice in September 1944. The agreement between Finland and the USSR restored the borders settled at the conclusion of the Winter War four years earlier. It also required Finland cede additional territory in the far north, among other terms.

The USSR traded its claim to the Hanko Peninsula (Map 3) in favor of a long-term lease of more desirable waterfront property known as the Porkkala Peninsula (Map 4) which became a Soviet military base. The land was returned to Finland in 1956. Today, the Finnish-Russian border is about 100 miles (160km) from Saint Petersburg.
Postscript. . .
. . . had Stalin waited for winter to pass before starting his operation against Finland (or if his forces had been better prepared), it’s possible the Finns would now be celebrating 30+ years of independence from Soviet rule – same as the Estonians, Latvians and Lithuanians. Outcomes for Sweden and Norway may have been quite different as well.
. . . existence of secret protocols was long denied by the Soviets (up until 1989). Of course, acknowledging the protocols would have exposed the lie that Estonia, Latvia and Lithuania had joined the USSR voluntarily.
. . . the Soviet party line was that each of the three Baltic States had independently and organically requested security assistance from Moscow. This, of course, was not true. In all three cases, legitimate governments were forcefully coerced from office in the summer of 1940 and replaced by communist puppets doing Moscow’s bidding.