Sun Tzu's Art of War said, soldiers are expensive to win, but not for a long time  It means that the tactic of using troops is expensive and the victory lies in the quickness of the battle  However, Mao Zedong's on protracted War advocated a protracted war, and the Chinese army won the War of Resistance against Japan by protracted war
During World War II, the German army won a series of victories by blitzkrieg and was dragged into a protracted war after entering the Soviet Union. As a result, Hitler repeated the mistakes of Napoleon.
 It can be seen that on protracted War and Sun Tzu's Art of War are inconsistent in the view that soldiers are not expensive for a long time