When the NRA forced back the Beiyang government-aligned "National Pacification Army" warlord coalition to Shandong province in May–June 1927, the Japanese, who considered the province within their sphere of influence, deployed four-thousand troops of the Kwantung Army to the cities of Qingdao and Jinan in what they called the "First Shandong Expedition" (第一山東出兵, Dai-ichi Santō Shuppei), ostensibly to protect Japanese civilians in anticipation of an NRA advance.[8][9] NRA commander Chiang Kai-shek wanted to keep his troops away from Jinan, avoiding what he viewed as a useless and potentially costly clash with the Japanese.