In our opinion, the reason that gave rise to a whole series of such large-scale catastrophic defeats of the Red Army at the beginning of the Great Patriotic War was an extremely unfavorable combination of several factors. Firstly, this was a direct consequence of the erroneous provisions of the Soviet military doctrine about the nature of the start of a future war with Germany. Secondly, the military disaster was the result of the low combat capability of the Red Army. Thirdly, the mistakes of the country's political leadership in determining the timing of the Nazi attack on the USSR.