1On April 5, 942, the German high command issued the No.41instruction on the Eastern Front. Hitler was forced to give up the all-round attack strategy he had been pursuing and adopt the successive attack strategy, demanding "annihilating the remaining living forces of the Soviet Union and seizing its most important war economic resources as much as possible" to regain the strategic initiative. The basic principle of fighting is: "the troops in the middle of the road slow down their attack speed;" In the north, Leningrad should be captured and land contact should be established with the Finnish army; On the south wing of the army front, it should be wedged into the Caucasus. "Considering the results of the winter campaign, the existing military weapons and transportation conditions, the above goals can only be achieved gradually.