The Soviet-German battlefield in World War II can be said to be the largest and most brutal battlefield of the war, where Germany invested the main combat forces, and the Soviet Union also used its national strength to resist the German army's step by step. Looking at the relations between the Soviet Union and Germany now, it is not difficult to find that although the two countries had "friendly relations" before the outbreak of war, they were also the product of mutual compromise and restraint. Just when the German army attacked Britain and France, the Soviet Union provided them with a large amount of food, armaments and other materials, but the two sides still understood that this was only a delaying strategy, and sooner or later a big war would break out between the Soviet Union and Germany...
As for why the tacit war broke out, there are different views.
On the surface, there is a distinct ideology between the two sides, and for Britain and France, Germany and the Soviet Union are dictatorships, and Britain and France want to lead Hitler's "evil water" to the East. As far as the Soviet Union is concerned, Germany, Britain, and France are all democratically elected governments, and they are all very hostile and exclusive to themselves, and they must lead the "evil water" to the West so that they can reap the benefits themselves. In this context, there are irreconcilable ideological contradictions on all sides.
As far as Germany is concerned, Britain and France are the victorious countries in World War I, and in the post-war Versailles system, Germany was exploited and squeezed, so that Germany lost power and humiliated the country, cut off land and reparations, the German army lost its former dignity, Germany's political environment became chaotic, the economy fell to the brink of collapse, and the domestic people were not happy, and such a social environment also provided a basis for Hitler's rise to power.
Russia once put Germany in a two-front war in World War I, consumed a lot of Germany's national strength, and laid the hidden danger for the final defeat. At the end of World War I, the Kiel sailors, who were seduced by the "red" of the Soviet Union, rebelled, which quickly led to Germany's rapid defeat in the war, so many Germans opposed the Soviet Union and held an unforgettable hatred for it.
In Hitler's propaganda, Germany was a superior nation, and Britain, France, and Russia were all old hatreds, and they had to be cracked down to avenge the hatred of the country. The Slavs of the East are more like inferior peoples like "insects", but such peoples occupy a large amount of land, population and resources, and their land is vast and their mineral resources are everywhere.
Hitler's name and propaganda of speech plunged Germany into a "frenzy" of economic crisis and the blow of the Allies, and the rich resources and vast land were so attractive that Hitler wanted to occupy Eastern Europe, drive out the Slavs there, and fight to the end for Germany's "living space".
At the same time, Hitler saw the performance of the Great Purge within the Soviet Union and the war against Finland in the early days of World War II, which made Hitler believe that his fierce enemy was nothing more than a figment, like a "broken house" that would fall down as long as it was kicked.
It was in this context that the Germans and Soviets inevitably went to war. After the outbreak of World War II, Germany soon occupied many European countries such as western Poland, France, the Netherlands, Belgium, Norway, etc., which made Hitler's greed uncontrollable, and he believed even more that Germany could easily defeat the Soviet Union with such a powerful force, so the Soviet-German war inevitably broke out on June 22, 1941...