Second, at the beginning of the war, the Soviet army was violently attacked by the Germans in the air, and the Soviet army lost more than 1000 fighters in the first round of air strikes, which led to the complete change of hands of Soviet air superiority at the beginning of the war. The Soviet army, which lost its air superiority, immediately lost the initiative on the battlefield.
Third, the Soviet frontline commanders adopted the wrong tactics. When the Germans flooded across the Soviet-German border with the roar of Stuka bombers. The Soviet frontline commander opened the Soviet supreme operational plan stored in the front line at the first time, and it was never allowed to open it without the authorization of the superior. This operational plan was formulated by the Soviet General Staff against Germany in the future Soviet-German war. The operational plan is a large-scale offensive operational plan. The idea of the plan is that under the cover of tens of thousands of new Soviet fighters, the Soviet army attacked Romania under German control from Stalin's defense line, cut off Germany's oil supply and forced Germany to yield to the Soviet Union.
Soviet front-line commanders hurriedly opened the information safe, read the wartime operational plans of various units, and directed the Soviet army to launch a partial counterattack against the Germans according to the contents of the plan. As a result, the Germans cut off the supply of oil and ammunition to the Soviet Union and the contact with the rear. Under the cover of air power, the Germans quickly attacked, jumped around and carried out blitzkrieg, and quickly completed the steel blockade of millions of Soviet troops on the front line and completed the strategic encirclement of the Soviet troops on the front line. As a result, the active troops on the western front of the Soviet Union suffered heavy losses at the beginning of the war.
Fourth, at the beginning of the war, the Soviet army failed to complete the upgrading of new advanced equipment. The main battle equipment of the Soviet frontline troops lags far behind the Germans in performance. As a result, these outdated equipment became the living targets of the Germans.
Fifth, the great purge caused the Soviet army to lose a large number of frontline commanders with actual combat experience. Front-line commanders are inferior to German officers in quality. In the face of adversity, tactics are dull. The training level and quality of soldiers are not comparable to those of German professional soldiers.