直皖戰爭
In order to cement their control over Manchuria during the Republican era, Russia and Japan continued to invest in railroads. Japan forced the Twenty-One Demands (shortened to thirteen after initial negotiations) as an ultimatum to President Yuan Shikai, extending their territorial lease, allowing subjects to have land loaned to them, and giving them the rights to the Jilin–Changchun Railway. Another Japanese coup was planned in 1915, but was canceled. The Japanese continued to exert their influence in China through loans, abandoning their aggressive stance. In 1918, the Japanese lent Duan Qirui the Nishihara Loans, of which ten million yen for the Jilin-Huining Railway and thirty million for developing industries in Jilin and Heilongjiang. Twenty more were used to invest in planned railways. However, most of the money was used to fund Duan Qirui's army and was used in the Zhili–Anhui War. Zhang Zuolin in Mukden borrowed three million more from Japan to reorganize his finances.