Answer: Soviet Union
Explanation: The Battle of Stalingrad is the biggest and bloodiest battle during the Second World War. It was run in the period from August 23, 1942 to February 2, 1943, between German aggressors and their allies from one, and the Soviet troops on the other side. It represents the first major defeat of the Germans in WWII that they publicly acknowledged. The main counteroffensive by the Soviet troops was prepared and carried out during the winter, because, like many times before, the enemy is not well prepared for the conditions of the Russian winter.