The winter war
The Soviet order of battle on the 30th of November was the 7th Army on the Karelian Isthmus, with the 8th, 9th and 14th Armies spread out above Lake Ladoga with various objectives. This amounted to 250,000 Red Army soldiers with a variety of equipment and training, ranging from well equipped crack units, to scraped together green grunts that had been placed in a uniform only days before. A significant amount of armoured units and artillery pieces were to be used in the blitzkrieg style tactics that had worked so well for the Germans in Poland and Zhukov in Khalkin Gol. The Soviets had an overwhelming air superiority, which the Allies later noted was a virtual necessity in their victory in WWII. Against this, the Finns had an army of 160,000 troops organised into units depending on their home region, a complete lack of mobile armour, and a minuscule amount of ancient WWI biplanes.
As soon as the first Soviet bombs fell on Helskini, President Kallio officially rejected Mannerheim's resignation he had days earlier agreed unofficially to accept, and Mannerheim was immediately appointed commander in chief. Knowing that Finland could not resist the Red Army for long, Field Marshal Mannerheim was counting on three options with fighting. Knowing the Russians could only successfully attack Finland around Lake Ladoga, as roads further north were brutally inadequate, Mannerheim knew that the Finns could oppose the Soviet forces there and delay them for a few weeks at the least. In this time, hopefully the West would see Finland's plight and come to its aid. Failing that, Stalin might see the stubborn fighting, and rather than be drawn into protracted warfare, settle for a negotiation that would still see a sovereign Finland. If these two options failed, the Finns would fight to the last man, last dollar and last bullet, sure to leave the name Finland in the annals of heroism, even if it did not exist as a country after the war.
Besides Mannerheim's realistic plan to allow Finland to continue as an independent state, issues of Soviet misunderstanding of the situation in Finland and intelligence would work in Finland's favour. The blitzkrieg style tactics worked well in the plains of Khalkin Gol and Poland, true, but that was a different story on the vast forests of Finland. Poor roads did not support a blitzkrieg, neither did communication centres deep behind the lines providing no objectives to capture for the Soviets. The Soviets did not think to paint their tanks white to camouflage against the snow until weeks into the campaign, and also didn't think to have adequate clothing for such a cold winter. The presence of tons of waste resources such as propaganda leaflets and state- of-the-art anti-tank guns that were useless against Finland's non existent tanks just as they were useless against pretty much anything else. The expected fifth column of communists within Finland never appeared, having emigrated to the USSR in the 30s, with the socialists that remained fighting alongside their brothers. What sounded easy on paper, was not going to be easy in real life.
The key to attacking and defending Finland was the Mannerheim Line on the Karelian Isthmus. This eighty mile line of fortifications is strongest at the ends where the land meets the waters of the Gulf of Finland and Lake Ladoga, and fixed coastal fortifications shoot high calibre cannons. Even with the cold winter, the ice on this part of Lake Ladoga was too weak to support heavy equipment, and ice on the Gulf of Finland cannot support it until late February, so outflanking the line is out of the question. The sector of the line containing the road which was the shortest route from Finland to Leningrad, known as the "Viipuri Gateway", contained ground hard in the freeze, ideal for mobile armour. The Red Army spent most of it's forces in the Karelian Isthmus, and found their technology were not the war winning devices they thought they were, and over time the Finns learnt how to counter in their own way. The Finns lent the name "Molotov cocktail" to the bottles of petrol with cloth stoppers that were lit and then thrown, used to counter the Soviet tanks. The tank hunter units using these homemade bombs had a high casualty rate - about 70 per cent - but there were plenty of Finns prepared to fight the Russians this way. Through the Soviet's misuse of their soldiers and armour, the Finns courage, and the use of night-time by the Finnish soldiers to rebuild the gaps in the line, with barbed wire, mines, tank blockades and the like. But Marshal Mannerheim and every Finn knew that over time, all three of these factors would change through change of Russian tactics, Finnish tiredness and lack of reinforcements.
Makeshift weaponry was not the only development to augment the Finnish soldier's lack of resources and manpower. The army also developed new tactics with time. One of the most popular was the motti tactics. In Finnish, a motti is a pile of wood with stakes holding it in place, which will eventually be cut up for firewood. The motti tactics was to approach and pin a Soviet column that adequate information has been gathered about. Then with a focus on concentration of firepower, the column would be attacked and divided into many isolated parts. The key was not to make the isolated part too large to put up a struggle which it can use to break out of the motti, or defend until Red Army reinforcements arrived. Then the mottis could be dealt with, beginning at the weakest, and cold, hunger and lack of supplies could weaken the stronger ones. This tactic was used to supplement the lack of ammunition, artillery and manpower the Finns had.
In the north of Finland's border with the USSR, guerilla tactics were the favoured method of fighting. What few roads there were, the Red Army stuck to them, for deviating into the forest was a sure death, whether to the terrible cold or a Finnish sniper. The invading soldiers were wholly unprepared for winter in the north: being too overloaded, too underdressed, and some Soviet citizens from warmer climates, such as Soviet central Asia, died in the cold of the north. The Finnish ski soldier is still the enduring image of the Winter War, even though the war was decided in the more conventional fighting on the Karelian Isthmus. At Suomussalmi, where Finnish ski guerillas destroyed two divisions of Soviets with little loss to themselves, was forged both the most popular victory of the Winter War outside of Finland as well as the enduring image of the ski soldier winning the Winter War. In reality, these victories did little in deciding the outcome of the war, and would have also been the case had the Soviets pulled off convincing victories. If anything, all they did was create false hopes in Western minds that free men can resist tyranny and win, which did not bode well for Field Marshal Mannerheim's plan to involve the West.
On the 1st of February, Stalin was tiring of the charade in Finland. He had replaced Voroshilov with Timoshenko in orchestrating the fall of the tiny Baltic republic that had thus far refused to submit, and a large artillery barrage began on the Karelian Isthmus, the largest since the German barrage at Verdun in the Great War. 600,000 Soviet troops amassed near the Mannerheim line, and on the 6th of February, the final Russian offensive began. Finally the Finns fears had come true, the Red Army had learned from it's previous mistakes just when Finland's soldiers were at their most timed, and ammunition the most low. Massed coordinated armour assaulted the line, and by the 14th, Mannerheim was worried enough to personally view the situation himself at the front. He know that if a massed army was thrown at the Mannerheim Line long enough, Finland couldn't resist. Older fortifications of the Mannerheim Line were abandoned first, then the whole line altogether as the Finns retreated to the secondary defensive lines.
When peace negotiations were reopened, Soviet terms were harsher than November 1939. The city of Viipuri would be ceded to the Soviets, as all the land on the Karelian Isthmus and around Lake Ladoga. Over 400,000 Finnish refuges would need to be resettled after the war, some 12% of the population. Finland would lose the port of Petsamo, as well as strategic points in the Gulf of Finland. Economically, Finland would also lose out, it would lose farmland and vital timber industries on the Karelian Isthmus, 100 power stations, and numerous farms. Ashamed, the Finnish politicians had no choice but to sign. It was better than total subjugation. The peace terms were to come into effect at midday on the 13th of March, 1940. They would not be accepted easily by the people of Finland, as in the words of Vaino Tanner: "Peace has been restored, but what kind of peace? Henceforth our country will live as a mutilated nation". In the coming months, Finland's politicians would be walking on tenderhooks to resolve issues peacefully with an increasingly frustrating and frustrated Soviet Union.