Mukden Incident (Manchurian Incident)

At about 10:20 p.m. on 18 September 1931 a small explosive charge was detonated beside the South Manchuria Railway line at Liutiaohu, a few kilometres north of Mukden (Shenyang). The plot had been prepared by Kwantung Army staff officers Col. Itagaki Seishiro and Lt. Col. Ishiwara Kanji, and was carried out by Lt. Komoto Suemori of the Independent Garrison. Damage to the track was slight and a train passed over it shortly afterwards.

Claiming a Chinese attack, the Kwantung Army immediately assaulted the nearby Beidaying barracks of the Northeastern Army and occupied Mukden by the following morning. Its commander, Lt. Gen. Honjo Shigeru, approved the expansion of operations along the railway. On 21 September the Korea Army under Lt. Gen. Hayashi Senjuro crossed the border without imperial sanction. The Wakatsuki cabinet in Tokyo adopted a policy of non-expansion but was unable to restrain the army in the field.

Within months Japanese forces had occupied most of Manchuria, and in March 1932 the state of Manchukuo was proclaimed with the former Qing emperor Puyi as its head. The League of Nations sent the Lytton Commission, whose report of October 1932 rejected the Japanese claim of self-defence; after the League adopted the report, Japan announced its withdrawal in March 1933.

In China the event is known as the September 18 Incident and is commonly regarded as the start of the fourteen-year War of Resistance. The site is marked by the 9.18 Historical Museum in Shenyang.