At the outbreak of WWII, when the Soviet Union attacked Poland from the East in September 1939, the Russian tanks were a jumble of obsolete, rumbling military vehicles of all sorts, all of them being lightly armored and armed with underpowered guns. They were fielded mixed with infantry units to provide fire support. This obsolescence of Soviet tanks was put in evidence when the Wehrmacht set Operation Barbarossa in motion on June 22, 1941. Flimsily protected, the Russians armored vehicles could do nothing to stop the German Panzer III and IV tanks, which were used in independent concentrated armored units that tore big holes in the Soviet lines. However, in December 1941, during the Battle of Moscow, when the Germans were at the gates of the city, the Red Army counter-attacked with new armored divisions equipped with a new type of Russian tank; the T-34, which greatly contributed to change the tide of the war. This massively-produced, well-armored, medium tank was followed by the IS-2, a powerful heavy tank introduced in 1943; these were the game changer in the tough war circumstances of the Eastern Front.
List of World War II Soviet Tanks
– T-26: a 9.5 ton infantry tank, armed with a 45mm gun
Below: the T-34, the most massively produced tank in the war