塘沽协定
After the creation of Manchukuo and subsequent military action by the Imperial Japanese Army, which brought Northeastern China east of the Great Wall under Japanese control, the Empire of Japan and the Republic of China signed the Tanggu Truce, which established a demilitarised zone south of the Great Wall, extending from Tianjin to Beiping (Peking). Under the terms of the truce and the subsequent He-Umezu Agreement of 1935, this demilitarized zone was also purged of the political and military influence of the Kuomintang government of China.