In combat, the biggest cause of confusion among Finnish soldiers were Soviet tanks. The Finns had few anti-tank weapons and insufficient training in modern anti-tank tactics. However, the favoured Soviet armored tactic was a simple frontal charge, the weaknesses of which could be exploited. The Finns learned that at close range, tanks could be dealt with in many ways; for example, logs and crowbars jammed into the bogie wheels would often immobilise a tank. Soon, Finns fielded a better ad hoc weapon, the Molotov Cocktail. It was a glass bottle filled with flammable liquids, with a simple hand-lit fuse. Molotov cocktails were eventually mass-produced by the Finnish Alko corporation and bundled with matches with which to light them. Eighty Soviet tanks were destroyed in the border-zone fighting.
By 6 December, all the Finnish covering forces had withdrawn to the Mannerheim Line. The Red Army began its first major attack against the Line in Taipale — the area between the shore of Lake Ladoga, the Taipale river and the Suvanto waterway. Along the Suvanto sector, the Finns had a slight advantage of elevation and dry ground to dig into. The Finnish artillery had scouted the area and made fire plans in advance, anticipating a Soviet assault.
The Battle of Taipale began with a forty-hour Soviet artillery preparation. After the barrage, the Soviet infantry attacked across open ground but was repulsed with heavy casualties. From 6–12 December the Red Army continued trying to engage using only one division. The Red Army next strengthened its artillery and brought tanks and the 10th Rifle Division to the Taipale front. On 14 December, the bolstered Soviet forces launched a new attack but were pushed back again. A third Soviet division entered the fight but performed poorly and panicked under shell fire. The assaults continued without success, and the Red Army suffered heavy losses. One typical Soviet attack during the battle lasted just an hour but left 1,000 dead and twenty-seven tanks strewn on the ice.
For many of the encircled Soviet troops in a pocket, (motti in Finnish), just staying alive was an ordeal comparable to combat. The men were freezing and starving and endured poor sanitary conditions. Historian William R. Trotter describes these conditions thus: "The Soviet soldier had no choice. If he refused to fight, he would be shot. If he tried to sneak through the forest, he would freeze to death. And surrender was no option for him; Soviet propaganda had told him how the Finns would torture prisoners to death."Also, this is classic:
On the eastern side of the isthmus, the Red Army attempted to break through the Mannerheim line in the battle of Taipale. On the western side, Soviet units faced the Finnish line at Summa, near the city of Viipuri, on 16 December. The Finns had built 41 reinforced concrete bunkers in the Summa area, making the defensive line in this area stronger than anywhere else on the Karelian Isthmus.All quotes are from Wikipedia article on the Winter war. (Russia won, in the end, by the way, and got the territory it wanted, but with bad long-term results. One of the worst results was demonstration of its military ineptness which proved to many Nazi generals — who were having serious doubts beforehand — as well as Hitler the presumed ease of attacking Russia.)
However, because of a mistake in planning, the nearby Munasuo swamp had a kilometer-wide gap in the line.:407 During the first battle of Summa, a number of Soviet tanks broke through the thin line on 19 December, but the Soviets could not benefit from the situation because of insufficient cooperation between branches of service. The Finns remained in their trenches, allowing the Soviet tanks to move freely behind the Finnish line, as the Finns had no proper anti-tank weapons. However, the Finns succeeded in repelling the main Soviet assault. The tanks, stranded behind enemy lines, attacked the strongpoints at random until they were eventually destroyed, twenty in all. By 22 December, the battle ended in a Finnish victory.