Following the establishment of Manchukuo, the Kwantung Army launched an operation to secure its southern frontier with China by attacking and capturing Shanhaiguan Pass at the Great Wall on 3 January 1933.

Declaring the province to be historically a portion of Manchuria, the Japanese Army initially hoped to secure it through the defection of General Tang Yulin to the Manchukuo cause.

The Japanese army's chief of staff requested Emperor Hirohito's sanction for the "strategic operation" against Chinese forces in Rehe.

On March 2 the Japanese 4th Cavalry Brigade encountered resistance from the forces of Sun Dianying, and after days of fighting took over Chifeng.

Chinese forces fell back in disarray to the Great Wall, where after a series of battles and skirmishes, the Japanese Army seized a number of strategic points, and then agreed to a ceasefire and a negotiated settlement (the Tanggu Truce) whereby a demilitarized zone would be established between the Great Wall and Beijing.