How accurate is the narrative of the Winter War being a Soviet war of conquest?
pretty inaccurate. while most history in english of the period minimizes finnish-nazi collaboration and demonizes the soviets, even a cursory reading of the available evidence disproves that narrative. while legally it might have been a war of conquest (assuming a soviet false flag) the geopolitical and military circumstances of the conflict provide a lot of justification for the ussr’s actions.
if you want a tl;dr, the right-wing finnish government posed a clear threat to the ussr, and the winter war can predominantly be seen as a necessary war that was demanded by the exigencies of capitalist aggression.
firstly, we have to remember that the government of finland, effectively headed by a brutally reactionary tsarist officer, was literally founded amongst the corpses of thousands of finnish communists, a large portion of whom were murdered by german intervention forces. often the finnish reds are depicted as being backed by the bolsheviks; this is horseshit as bolshevik material support was nonexistent due to the demands of the russian civil war. while the minutiae of finnish internal politics are beyond me, purges of finnish communists continued well into the 1930s, and the finns cooperated extensively with the right-wing governments of both sweden and estonia. on top of that, raids into russian-held karelia were very common in the 20s, and large portions of the finnish government fantasized about invading the ussr and creating a greater finland. the simple truth of the matter is that these kinds of anti-communist governments will, whatever the legal fictions they hide behind, stop at nothing to sabotage revolutions and bring down workers’ movements, and the finns proved themselves to be reactionaries pare excellence. in spite of all this, though, the soviets signed repeated non-aggression pacts with the finns, and even attempted to open up bilateral trade without much success.
secondly, regardless of the intentions of the finnish government, both their actions and the geographic realities of the region meant that finland posed a clear and present danger to the soviet union. starting in the 1920s, finland built a series of fortifications along the border with the ussr, appropriately named after that tsarist officer (mannerheim) i mentioned above. while that area did constitute a natural chokepoint, making it the best location for a defensive line, it also happened to be very close to the incredibly vital city of leningrad. those fortifications would not only constrain soviet operations in the region, but also provide a perfect shield and jumping off-point for an invasion of the most vulnerable and important area in the entire ussr. obviously, the soviets were extremely concerned about this, as
it would be trivial for even a small german force to attack from behind the mannerheim line and encricle leningrad. given their (justifiable) perception of the finnish governenment as brutally reactionary, and the obvious fact that war was coming, the security of leningrad had to be guaranteed. whether or not the mannerheim line was intended to threaten leningrad is of course impossible to ascertain, but it seems likely to me. while the finns trumpeted their neutrality, the ease with which they joined the nazis speaks for itself. anna louise strong also claims that finnish mobilization long predates the winter war, and that the nazis built a massive network of airbases in finland (far in excess of what the finnish air force needed) presumably to attack the ussr with, but i can’t find verification or denial of either of those claims.
in spite of all that, however, the soviets were still very conciliatory to the finns.
before the winter war started, the soviets attempted to negotiate a
trade of territory with the finns. if the finns abandoned the mannerheim
line and the territory around it (most of which was worthless), ceded a
few islands and let the ussr lease a port in southwestern finland, the soviets would give them an amount of territory in karelia easily twice the size of what the finns would give up. while the deal would open up finland to soviet invasion, the idea that the ussr would waste valuable resources in the face of an imminent war with germany, after having secured the approaches to leningrad, is ridiculous. the finns could very easily have accepted this deal, and the winter war need never have happened. the fact that they didn’t also implies what i assert above: the finnish goverment had as its goal the destruction of the ussr, and the winter war was a necessary measure to safeguard the revolution. even after the soviet victory, with finland at their mercy, the soviets merely took a large chunk of finnish industry, stopping short of regime change, humiliation, or permanent demilitarization. right-wing historians often claim that the soviets secretly wanted to conquer all of finland out of a vague imperialistic lust, but given the ease which with finland could have been assimiliated in either 1940 or 1944, this is obviously nonsense.
all in all, then, it’s pretty clear that the main causes of the winter war weren’t a soviet lust for conquest or imperial nostaliga, but rather finnish revanchism and the clear military threat posed to the soviet union. while a more conciliatory soviet policy and a different approach to the molotov-ribbentrop pact could have lead to peace, mannerheim’s obvious hatred of communism and the bitter memory of the finnish civil war probably meant that soviet leaders simply didn’t trust the finns enough to do so.
two codas: firstly, the narrative of horrific soviet incompetence during the winter war is only partially true. everyone obsesses over the first phase of the winter war, where the soviets did get cut to pieces by the finns, albeit in the face of massive logistical and environmental constraints. however, during the second phase of the war (only a few months later) the soviets managed to fix most of their problems and handily beat the finns despite their massive casualties secondly, no-one ever talks about the continuation war, wherein the finns provided massive amounts of vital nickel and logistical support to the nazis while consistently harassed the soviets after taking back their losses. while (alledgedly) the finns didn’t hand over many jews to the nazis, im sure the germans were still pretty happy with that deal.
thanks for the question!