Before the outbreak of World War II, Nazi Germany, in order to ensure that it would not be caught between the two sides, signed a secret contract with the Soviet Union, the Soviet-German Non-Aggression Pact, referred to as the Soviet-German Treaty. The signing of this contract led to the future Soviet-German aggression against Poland, which marked the beginning of World War II as the "Polish War".
The Soviet-German coalition spent 1 month using "blitzkrieg" to occupy Poland. But on June 22, 1941, Nazi Germany and its Axis allies launched the Barbarossa Plan, which directly tore up the Soviet-German Non-Aggression Pact. And began to invade the Soviet Union, followed by the outbreak of the Soviet-German War.
The Germans invaded the Soviet Union and lightning occupied most of the western part of the Soviet Union. It was not until half a year later, in the Battle of the German Invasion of Moscow (the Battle of Moscow) that the Soviets achieved their first victory. Because the German invasion was too fast, which depleted the physical strength of the German army, they also lacked winter war equipment and stable supply lines. Suddenly, the temperature plummeted overnight, and the German mechanized troops were completely unusable, and the Soviets had long been accustomed to such temperatures because they had lived in such a cold area for a long time. Immediately, the Soviets began to counterattack the Germans.
It was not until the spring of 1942 that Hitler decided to abandon his plan to attack Moscow again and instead began planning a new round of local offensives on the northern and southern fronts. At that time, the Japanese attacked Pearl Harbor in the United States, and Hitler felt that the war on the Eastern Front should be ended as soon as possible before the American army joined the European theater to weaken the Soviet Union.
As a result, a new round of local offensives by the German army soon aimed at Stalingrad. West and south of Stalingrad were the vast and fertile lower Don, Kuban and Caucasus regions, which were important producers of grain, oil and coal in the Soviet Union. After the German occupation of Ukraine in 1941, Stalingrad became the only traffic choke point in the central region of the Soviet Union to an important economic region in the south, and the strategic location was very important. If Stalingrad had been lost, the Soviet Union would have lost the oil, food, and industrial base needed for the war.
It just so happened that the Germans were in great need of these resources now, and before Hitler decided to attack Stalingrad, he had said: "If I can't get the oil from Maykop and Grozny, then I must end this war.". It can be seen that he is determined to capture Stalingrad.
On June 28, 1942, the Germans officially attacked Stalingrad, and the Battle of Stalingrad broke out. This war was the bloodiest battle in recent history, one of the most tragic battles in the history of human warfare. In the 199-day super-large-scale battle, the number of Casualties caused by the German and Soviet troops could not be counted. The casualties on both sides can only be estimated to be as high as 2 million, and although in the final stages of the campaign the Germans inflicted a heavy blow on the Red Army, the Red Army also nearly wiped out the German Sixth Army.
The Battle of Stalingrad, in which both the Soviets and Germans suffered heavy casualties, and the Battle of Stalingrad, together with the Battle of Guadalcanal and the Battle of El Alamein, which occurred at the same time, became a landmark event of the great turning point of the anti-fascist war.