144: Plans


The Winter War was starting, how did both sides plan to fight the war?



Hello everyone and welcome to History of the Second World War Episode 144 - The Winter War Part 2 - Plans. This week a big thank you goes out to Zak, Luke, and Brody for choosing to become members, you can find out more about becoming a member over at historyofthesecondworldwar.com/members. When the first shots of the Winter War were fired, neither side of the conflict was entirely unprepared for the the Soviet offensive. Soviet plans had been put in place over the preceding months as the possibility of invading Finland became a real possibility. For the Finns, they had in some ways been preparing to fight this war since they had won the Finnish War in Independence during the Russian Civil War. These preparations were most apparent, and most famous, on the Karelian Isthmus where through many years of hard work a series of defenses had been created which would be referred to as the Main Defense Line, although it would end up being better known as the Mannerheim Line, which is how foreign reporters referred to it during and after the war. But other preparations had also been made for a Soviet advance further to the north. Even with these preparations though, the general feeling by foreign military attachés was that the Finnish resistance, while perhaps fierce, would quickly be overcome by a Soviet attack. In this episode we will take a look at how both the Finnish and Soviet militaries planned to fight a conflict between their two nations, and the preparations that had been made on both sides of the border for the upcoming Winter War.

When discussing Finnish preparations for war, it is difficult to not start with the Mannerheim Line. The Line was partially caused by the geography of the region where the Finnish border had been drawn in 1920. The new border was quite close to Leningrad, only about 30 kilometers at its nearest point, and the Karelian Isthmus meant that any fortifications in the area would not have to be very long. It was such an ideal location that both sides would actually build up fortifications in during the 1920s and 1930s, with the Soviet defenses referred to as the Karelian Fortified Region. Both Soviet and Finnish military planners recognized that a line of defenses that spanned between Gulf of Finland to the south and Lake Ladoga to the north would be a major asset. There would be several different generations of fortifications built in the Mannerheim Line, starting shortly after the peace treaty was signed in 1920. During this period there were a large number of relatively simple concrete bunkers constructed, designed to hold a heavy machine gun. On the far left and right of the fortifications, which bordered the two bodies of water to the north and south, large coastal defense guns were mounted to prevent a naval attack. Some of the fortifications in these areas were actually old repurposed Russian structures, including the use of armored plates left behind by the Russian Imperial Navy. There was also some new construction during the 1920s and 1930s to bring them into the modern era this included the acquisition of several cannons of various sizes to bulk up the firepower of these coastal forts, most of them being World War 1 era guns that were purchased from abroad. In the second half of the 1930s there would be another generation of defenses put in place to greatly enhance the existing defenses. There would also be large new bunkers built during this time, called the ‘millionaire bunkers’ due to their size and expense. All of these new construction would result in bunkers that were not just larger, but also more capable, with reinforced concrete used in their construction and large crew quarters positioned within the structure which would allow for longer term occupancy. Along with new construction, many of the older bunkers were reinforced, with thicker walls and roofs put in place. There were limits to the number of resources and manhours that were available for these enhancements, and so various points in the line had to be prioritized over others. One of the highest prioritized areas, and one that this podcast will spend quite a bit of time discussing the actions around, was the areas to the southeast of a village called Summa. This was a roughly 16 kilometers stretch of land between the Summajoki River and Lake Muolaanjärvi which was made up of relatively open farmland, never great for the defense. On this 16 kilometer stretch of land 35 reinforced concrete defensive positions would be constructed, including many of the largest built within the entire Mannerheim line. In front of these positions barbed wire would be laid and thousands of mines would be positioned during the months leading up to the war. There had also been a series of anti-tank obstacles that were put in place with the goal of making it impossible to drive tanks over them, unfortunately the large stone monoliths were often too short to have the desired effect.

This is maybe a good moment to talk about the problems with the Line which would become apparent during the fighting. One of these was, as mentioned, the fact that the anti-tank obstacles were not able to actually cause Soviet armor any problems, because newer Soviet tanks used different suspension mechanisms which were able to handle the stone obstacles. But this was just the beginning, another major problem was that in most areas of the line the bunkers were placed too far apart, which prevented them from being able to provide mutual support, which would eventually allow the Soviets to defeat them in detail. Along with this, most of the bunkers did not have any weaponry larger than a heavy machine gun, this would be a major problem when the Soviet tanks arrived and were not met with any real anti-tank fire. The shortage of anti-tank guns was also matched by the general lack of heavy artillery support in any form. One of the critical needs of this kind of defensive line would be fire support to hit the attacking forces that were slowed by the defenses and their defenders, for the Finnish defenders this artillery often did not materialize due to a lack of guns and ammunition. When the war started the larger artillery pieces in the Finnish Army had only an estimated 19 days worth of ammunition, with even the smaller field guns only having an estimated 21, this was not a lot of ammunition to go around, and the rate of expenditure during the fighting would even higher than expected which made the overall ammunition system even worse. These challenges were well known to Finnish military leaders, and Mannerheim built his plans around the idea that, if the Soviets really wanted to they could push through the Line, it was simply cost them a very large number of casualties. But in a similar way that the Maginot Line became a major political and public relations item in France, in Finland a similar scenario would occur with the Mannerheim Line. Finnish citizens knew that it was being built and they believed it would give the Finnish military a real chance to defense a Soviet invasion. The line was so well known that the Soviets had detailed maps of the entire set of fortifications, although they were not consulted before the invasion, something that contributed to the early Soviet disasters. We also have to contend with the legacy that was developed for the line during and after the war. A bit of a spoiler here, but the first Soviet attacks on the line would not go well, and they would be very costly failures. This caused Soviet military leaders, and the later Soviet military historians, to play up the power of the line, because it had stopped the best attempts of the Red Army. If it had stopped the Red Army the defenses must be truly amazing. Over the decades this appraisal has been re-evaluated, with the overall strength of the line generally revised down every time. But, as with everything, you can get a lot of different opinions on the Line based on how an individual author values the defenses, the men manning those defenses, and the competency of the Red Army that was attacking it. That is why most contemporary Soviet accounts play up the power of the defenses, while contemporary and later Finnish accounts play up the skill and bravery of the men manning the Line.

Those men manning the Line were from the Finnish Army, which was similar to many other European armies at this time in that it was built around a conscription model where all men at the age of 18 were liable for military service, in the Finnish case for about a year. When the war started there were 10 fully equipped divisions, Each of these divisions had around 14,000 men in them, and in general most of the infantry was reasonably well trained and equipped. Funding levels were the primary constricting factor, there were the men for at least 4 more divisions but the money was not available to equip them. William Trotter in his book A Frozen Hell: The Russo-Finnish Winter War of 1939-1940 would try to put a positive spin on the budget situation in prewar Finland: “All those years of having to wring every ounce of value from every penny of the defense budget actually had some positive effects. The Finnish Army was “lean and mean,” experienced at getting the maximum effectiveness from its limited resources. Man for man, on its home ground, it was one of the toughest, best-led, most adaptable armies in the world. In spite of the scarcity of modern equipment, a spirit of calm confidence prevailed throughout the ranks.” That is a bit of a spin really, trying to make the negatives of lack of funding seem like a positive, it probably would have just been better if they had more equipment. But one thing that cannot be denied was the overall shooting skills of the Finnish infantry, which would become legendary. This would give rise to the Soviet belief that there were large numbers of dedicated Finnish snipers that were firing on their troops during the war, when in fact this was often just normal Finnish infantrymen, they were just really good shots. There were of course also snipers as well, with one of the most famous participants in the entire war being the Finnish sniper Simo Häyäh, who claimed in his memoirs to have killed over 500 Soviet soldiers during the war. Simo would earn the nickname of The White Death due to his kill counts, which were split between his bolt action rifle, with only iron sights, and a Suomi submachine gun. The Sumoi was a good example of innovative design, the biggest problem was that it could burn through a lot of ammunition very quickly due to its maximum fire rate of 900 rounds per minute, otherwise it was a very dependable and deadly design. There were only a few hundred per division when the war started, but that number would steadily increase throughout the course of the fighting, with many men seeking them out anytime one was available as a replacement for their standard issue bolt action rifles. It would go on to be copied by the Soviets in the form of the PPSh submachine gun that would be used during the Second World War. The greatest compliment for a weapon has to be that it is copied by the military that it was designed to fight against. But Simo was not the only Finnish sniper that would rack up a large number of kills, using their knowledge of the terrain and Finnish weather to their great advantage. But no matter how many men were killed with rifles, what became a serious problem was how to deal with the Soviet advantage in modern military hardware because the Finnish Army was lacking was any large armored or mechanized units. This was primarily a funding problem, with a combination of foreign rearmament efforts and the lack of domestic production facilities preventing any efforts to bulk up Finnish Units was vehicles. When it came to dealing with Soviet tanks, well the first antitank guns for the entire Finnish Army arrived from Sweden just weeks before the war started. Many of them were not even sent to the front in time, and even when they got there some of them were not used due to a lack of training. This issue was larger than just not being able to destroy the tanks as well, as it also meant that the Finnish units were overall unprepared mentally to deal with modern armored vehicles, they didn’t know how to react to them or if there was anyway that their units could destroy them. This would result in several instances of panic during the early actions of the war.

When it came to how Finnish leaders planned to use the divisions that were available, most of the plan was dictated by geography. Most of the border with the Soviet Union was heavily forested areas, with few large and well traveled roads/ This meant that the best way to structure the Finnish military was around small unit operations, with those units prepared and trained for independent operations in wooded, and possibly snow covered, areas. This also required the use of less conventional tactics, what we might refer to as guerrilla tactics, with ambushes and raids playing heavily into Finnish planning. These independent unit tactics were also required due to the vast distances that some Finnish units were required to cover in northern Finland, the North Finland Group made up of Civic Guards, border guards, and activated reservist units, all second class units were required to defend 625 miles of the border starting on the northern coast starting at the Arctic Ocean. To their south would be 2 divisions of the regular army manning 60 miles north of Lake Ladoga, which Finnish planners believed would be required to hold back 5 Soviet divisions, although the Soviets would actually send 12 divisions into this area. But it was believed that the war would be won or lost on the Isthmus, and so 6 out of the 10 regular Finnish Army divisions would be placed in the Mannerheim line on the Isthmus. This allowed for two divisions to be held in reserve. This basic structure of troop placement was in line with the VK2 Warplan that was developed before the start of the War by Finnish military leaders. VK1 had been a plan that would have seen Finnish attacks into the Soviet Union, which would not be a feature of the fighting during the Winter War. VK2 was built around the idea that the primary Soviet focus would be on attacking across the Isthmus and no major Soviet actions would be taken against the Finnish forces more than 100 kilometers north of Lake Ladoga. Mannerheim, overall, did not believe that the Finnish forces were capable of complete victory, and instead he hoped that they would be able to put up enough of a defense to allow for some kind of political settlement to the war. Or in Mannerheim’s words, he hoped for “the most honorable annihilation, with the faint hope that the conscience of mankind would find an alternative solution as a reward for bravery and singleness of purpose.” The chances of any kind of success were greatly boosted by Finnish preparations in the months before the fighting occurred, because as tensions rose between the two nations efforts were made to do whatever could be done to boost the defenses along the border and the training of individual soldiers. Here is a quote on these preparations from historian Bair Irincheev: “Throughout October and November Finnish troops built additional fortifications and performed intensive combat training at squad-platoon-company-battalion level, with live ammunition firing and advanced tactics courses. Counter-attacks against Soviet breaches of the main defence line were rehearsed time and again. When war began, the main defence line was indeed home turf for Finnish troops: they knew every inch of the battlefield like their back garden. These two months of training and preparation played a crucial role in the battles of December 1939, largely contributing to the Soviet failure.”


While the Finnish leaders and soldiers were doing everything in their power to prepare for a Soviet attack, Soviet leaders and soldiers were preparing to launch that attack. There had been some Soviet planning for an invasion starting in 1936, although at the time only vague outlines of plans were drafted, nothing like the detail that would actually be required to launch an invasion of another country. These plans were also quite cautious in their approach, taking a slow and steady approach which would not be favored by some Soviet leaders including Stalin when it came time for the actual invasion in 1939. Instead the plans used during the Winter War were mostly created in November 1939, and the generally underestimated the Finnish defenders and the effects that Finland’s terrain and weather would have on the attacking Soviets. The general plan was simply to overwhelm the Finnish defenders with a massive ground attack along the entire frontier, these ground attacks would then be supported by large air raids both on Finnish military formations and civilian population centers. In theory, this massive push would be impossible for the Finnish Military to meet in all of the various areas and so resistance would eventually fall apart. The change from a cautious approach to a more bold attack was caused by two changes: the overconfidence that would be present in the upper echelons of the Red Army after the invasion of Poland and the influence of the successful German attacks in Poland. In late September the Red Army’s advances into Poland had been impressive, capturing 200,00 square kilometers in just a few weeks, but as we discussed back in the September Campaign episodes, this was against a foe that was already struggling against the German attacks. The nature of those German attacks would also be inspirational for the Red Army in its planning. The quick nature of the German attacks had caught most observers by surprise, and the Red Army hoped to duplicate the quick German successes with some of their own. The geography of the areas involved was very important, and would be a major reason that German style “blitzkrieg” attacks would be much harder to pull off in Finland. In Poland, and in many parts of Europe, there was a combination of generally open terrain and large road networks, neither of these were present in the areas of Finland that the Red Army would need to attack through. And speed would be important, because the Soviet offensive would really only have a few weeks to be successful before winter weather would start to be a serious problem. But not everyone was as confident, here is a quote from General Meretskov in a report submitted in late 1939 but before the start of the war: “The terrain of coming operations is split by lakes, rivers, swamps, and is almost entirely covered by forests. … The proper use of our forces will be difficult. … It is criminal to believe that our task will be easy, or only like a march, as it has been told to me by officers in connection with my inspection.” I quoted Meretskov here because he was the commander of the Leningrad Military District and would be in overall command of the four Soviet Armies that would take part in the attack against Finland. He would also be in direct command of the 7th army that would be launched against the Karelian Isthmus, the most important area in the entire Soviet attack. The 7th Army, with 14 divisions, including around 1,000 tanks and other vehicles would attack directly into the Mannerheim line, aiming to push through it to Viipuri and then onto Helsinki. To the north of Lake Ladoga the 8th Army would have 6 divisions with the goal of attacking to the west, advancing beyond the lake and then moving south to attack the defenders of the Mannerheim line from the rear. Further to the north was the 9th Army with 5 divisions who had the job of just advancing westward into Finland with the goal of reaching Finland’s Western border with Sweden to cut the nation in half. Finally the 14th Army in the far north would attack the arctic port of Petsamo and then proceed to Rovaniemi. Overall it was certainly a bold plan, but there would be some mistakes made in how it was constructed.

The number one problem was one of emphasis. The Karelian Isthmus was the key, and not just the most important but almost the only area that actually mattered, which is why the Finns had put so much effort into building up its defenses over the years. Instead of focusing all of its efforts in this area the Soviet leaders would spread out their forces all along the border. This was especially problematic further north beyond the areas around Lake Ladoga, because the geography just did not allow for large scale troop movements, the forests were just too dense and there were not enough roads. And the roads that were present mostly just served to funnel the Red Army into nice tight little corridors that were easy targets for Finnish attacks. This would be a major feature of the fighting in the north, and the long columns of infantry and vehicles would be setup for some of true military disasters. Another problem was one of the soldiers involved. The Red Army was heavily conscript based, with most of its soldiers having very little experience in the military, and also very little experience in the environment that they would be fighting in. There were major differences in the weather between Southern Russia and the arctic circle where some Soviet soldiers would be fighting. Another problem was an underestimation of Finnish unity .One of the things that would be done very quickly after the invasion started was setting up a Soviet puppet government, with the idea being that this government would be a rallying point for Finns that were unhappy with the current government, like Finnish Communists. But the Finnish Army would enjoy universal support from the Finnish people as well, even from Finnish Communists, with one Finnish Communist leader saying: “These are not the times for political discussions, but one thing I will say: I have always understood that revolution was a thing that came from within, whereas war is a thing that comes from without. As a communist, therefore, I believe that communist Russia is wrong to attack us; and that my duty is to help defend the workers of Finland against attack from without.” So the Red Army had an overly ambitious plan, which did not focus on the most important areas, executed by poorly trained soldiers, and based on the hope that the nation they were attacking into would at least partially welcome the Red Army with open arms. Things were not going to go well.