had misgivings about whether it was prudent to launch the expedition, his party, the Rikken Seiyūkai, had run on a platform of "protecting nationals on the spot" in the February 1928 election, limiting his ability to moderate the Japanese response. Even before Tanaka had given the order, troops under the command of General Fukuda Hikosuke had begun arriving in Jinan via the Qingdao–Jinan railway, possibly as early as 10 April. This was the first serious case of unilateral action by the post-Meiji Restoration Japanese military. The first substantial group of 475 troops, however, arrived in Jinan from Qingdao on 20 April. They were followed by over 4,000 more troops over the coming days. The arrival of the Japanese troops in Jinan, just as the Beiyang-aligned forces had retreated there, prompted suspicions about whether the Beiyang warlords had asked for a Japanese intervention. This was used as propaganda by the Kuomintang, though Beiyang government leader Zhang Zuolin denied doing any such thing. Both the Beiyang government and the KMT government in Nanjing protested against the Japanese action, deeming it a violation of Chinese sovereignty. As the NRA launched a pincer attack on Jinan, the railways to Qingdao and Beijing were damaged, preventing warlord-aligned troops from receiving reinforcements. This also brought the NRA in conflict with the Japanese, who were guarding the Qingdao–Jinan railway, though no violence broke out at this stage. On 29 April, chaos erupted as the warlord troops began to flee northwards across the Luokou Yellow River Railway Bridge, abandoning Jinan. As they left the city, the warlord forces were reported to have engaged in looting, though Japanese-inhabited areas continued to be protected by Japanese troops. Public dissatisfaction with the presence of the Imperial Japanese Army in Shandong became increasingly evident, their presence viewed as a new attempt by the Japanese to seize control of the region, as they had in 1914 during the First World War. NRA troops marched into Jinan over the course of 30 April and 1 May, and took control without trouble. On 2 May, Chiang Kai-shek began negotiations with the Japanese to withdraw their troops, gave assurances to Japanese Major General Ryū Saitō that there would be no disruption in Jinan, and ordered his troops to proceed northward from Jinan with haste, so as to avoid any potential conflict. Following the negotiations, Saitō decided to begin preparations to withdraw the Japanese troops, and said