This change in policy came at a time when Japan was in the midst of a severe economic crisis from the Great Kantō earthquake and successive economic depressions , and caused both alarm and irritation in the Kwantung Army leadership . The situation was further complicated by the success of the Northern Expedition led by Chiang Kai-shek of the National Revolutionary Army , in which the Kuomintang successively defeated Sun Chuanfang , Wu Peifu and other warlords of the Northern Faction , as well as the Beijing government controlled by Zhang Zuolin . The Nationalist army appeared poised to restore its rule over Manchuria , which was still officially claimed as part of the Republic of China
Great Kantō earthquake
1923 Great Kantō earthquake
Huanggutun incident