As Condition for the Rise of Mao's Single Party State, how can this event be said to have strengthened him?

the Japones invasion of Manchuria was perfect for mao at that time becuase he was the only leader who made an effort to attack the japones instead of turing on his own people as Chang did. it was really beacuse of Chang's refusal to unite with the communest to destroy the japones and his willingness to work with the warlords that mao was able to strengthen himself in the eyes of the people as some one who stood for china's rights. The people saw Mao's willingness to fight the japones as a sign of strength, they felt that, finaly, here was a leader who was intrested in the rights of the commen people.