Why did Germany gain the upper hand at the beginning of World War II?

Early Germany was at a considerable disadvantage in equipment. Germany achieved great success in the early stage for the following reasons.

First, it has great advantages in strategic thinking. At that time, Britain and France were still in the trench warfare stage of World War I, relying on maginot line, heavily defending the Belgian region, and distributing tank troops to infantry troops instead of using them centrally. Germany concentrated on the use of tank troops, boldly interspersed and surrounded by divisions, and the task of destroying the enemy was completed by the subsequent infantry units.

Second, Germany has first-class military generals, first-class officers and first-class soldiers, thanks to the Prussian tradition. Prussian soldiers have been recognized as the best in Europe since the time of King Frederick. As the first country in the world to set up a staff headquarters, Germany's staff system and quality are also superior to other countries.

Third, Britain and France underestimated the war. Judging from the current data, the Soviet Union was preparing to take the initiative to attack Germany at that time, which greatly improved the border traffic and created considerable convenience for Germany to attack the Soviet Union later. On the other hand, the Soviet Union has just gone through a big purge, most experienced and qualified officers were killed, and the newly appointed officers and generals are generally of low quality. Coupled with Stalin's disastrous "military talent", the Soviet Union's command and performance in the early stage of World War II became a joke. (See also the imbecility of the Soviet Union in the Soviet-Finnish War before World War II. )

Another person thinks that if Germany completely handed over its troops to the General Staff, instead of its head of state who likes to say, "You only know military affairs, but don't know politics", before attacking the Soviet Union, it would control the Mediterranean coast, cut off the ties between Britain and India and force the British Empire to accept decent peace, and World War II might have a different ending.