Operation Chahar

Operation Chahar
	Part of Second Sino-Japanese War
	; Chinese soldiers, pictured by the Great Wall of China in Laiyuan in 1937
Date	8 August 1937 – 17 October 1937 ; (2 months, 1 week and 2 days)
Location	Vicinity of Beiping and Chahar – Suiyuan
Result	Japanese victory
Belligerents
Japan Mengjiang; Manchukuo ;	China
Commanders and leaders
Kiyoshi Katsuki ; Shigiyasu Suzuki ; Seishirō Itagaki ; Hideki Tojo ; Demchugdongrub	Tang Enbo ; Chiang Kai-shek ; Yan Xishan ; Fu Zuoyi
Strength
90,000 Kwantung Army troops; 60,000 Inner Mongolia and Manchukuo troops	7,432 officers and 122,910 soldiers
Casualties and losses
Chinese Claim : 8,652 casualties; Japanese Claim :; 5th division : 1,482 casualties; 2nd mixed brigade in the battle of Zhangjiakou : 529 casualties; 15th mixed brigade in the battle of Datong : 176 casualties; 1st and 11th independent mixed brigades : 902 casualties	Western Claim : 26,000 casualties; Chinese Claim :; 15,710 killed; 34,080 wounded; 479 missing

Operation Chahar (Japanese: チャハル作戦, romanized: Chaharu Sakusen), known in Chinese as the Nankou Campaign (Chinese: 南口戰役; pinyin: Nankou Zhanyi), occurred in August 1937, following the Battle of Beiping-Tianjin at the beginning of Second Sino-Japanese War.

This was the second attack by the Kwantung Army and the Inner Mongolian Army of Prince Demchugdongrub on Inner Mongolia after the failure of the Suiyuan Campaign. The Chahar Expeditionary Force was under the direct command of General Hideki Tōjō, the chief of staff of the Kwantung Army. A second force from the Beiping Railway Garrison Force, later the 1st Army under General Kiyoshi Katsuki, was also involved.