Why did the Germans make mistakes in the Soviet-German battlefield?

First of all, soviet strike was wrong. Any country that wage war on two fronts will undoubtedly fail.

Secondly, the strength of the Soviet Union alone far surpassed that of Germany. Before the war, it was just an careless attack.

At that time, the Soviet Union had13.8 million troops. In order to prevent Japan from attacking from the east, 6 million troops were deployed in the Far East and Central Asia. Germany's attempt is: Germany goes south, Japan goes north and attacks the Soviet Union. Unexpectedly, in the battles of Zhang Gufeng and Nomenkan, Japan was beaten everywhere and was forced to sign a peace treaty with the Soviet Union. After the signing of the treaty, the Soviet Union dispatched 3 million troops to participate in the Soviet-German battlefield, and Germany was defeated. Later, the Soviet Union wiped out 800,000 Japanese Kwantung Army with 3 million troops.

It is always a joke that a small country wants to be a big country.