塘沽協定
The Kuomintang military committee in Peking appointed General Fu Zuoyi as commander of Chinese 7th Army Group, and tasked him with providing Jehol border security. At the end of April, when the advancing Japanese forces approached Miyun, He Yingqin anxiously redeployed Fu Zuoyi's troops to strengthen the Peking's defenses eastwards to Changping leaving the defense of the Chahar border empty. The Japanese and Manchukuo armies seized the opportunity on May 11, and quickly following up on Liu Guitang's advance, seized the Dolonnur region, and subsequently took Guyuan, just prior to the signing of the Tanggu Truce of May 31, 1933.