Why didn't the September 18th Incident belong to War of Resistance against Japanese Aggression?

Why didn't the September 18th Incident belong to War of Resistance against Japanese Aggression?

193 1 year, Japanese imperialism flagrantly launched the September 18th Incident. Chiang Kai-shek ordered "absolutely no resistance", and the Northeast Army gave up Shenyang City without firing a shot. The Japanese army pushed its luck, and in more than four months, Liaoning, Jilin and Heilongjiang provinces all fell. ?

After Japan occupied the northeast of China, the people of China began an armed struggle against Japanese imperialist aggression. However, before the Lugouqiao Incident (July 7th Incident) in 1937, a national ethnic war could not be formed.

Lugouqiao Incident (also known as July 7th Incident)?

1On the night of July 7th, 937, the Japanese invaders suddenly attacked 29 army, the local China garrison, near Lugou Bridge in the southwest of Beiping, in the name of military exercises, and 29 army rose up to resist. China's Anti-Japanese National Liberation War began.

On August 1937 and 13, the Japanese army attacked Shanghai again, and was also stubbornly resisted by the defenders of China. China gradually ended the abnormal situation of giving way to the Japanese invaders and began an organized all-round war of resistance.