At the turn of spring and summer in 1942, the Japanese army captured Burma and immediately prepared to attack west Yunnan. They were expected to fight along Burma Road, conquer Yunnan and threaten
Chongqing. On May 4, 1942, the Japanese army invaded
Longling County, and at the same time dispatched 54 aircraft to carry out a violent bombing of
Baoshan, Yunnan, the Millennium Ancient City; on the 10th, the Japanese army invaded the border city of
Tengchong. At this point, a large area west of the Salween River (Nu River) fell into the hands of the Japanese army. The 71st Army of the Chinese Expeditionary Force set up defenses on the east bank of the Nu River, repeatedly frustrated the Japanese army's attempt to move eastward, and thus stabilized the war situation, and confronted it across the river for two years. At that time, after the Burma Road, which was once the only land international transportation artery, was cut off, a large amount of military supplies to China could only be transported by the US Air Force through "
The Hump" with much difficulty and no security. In order to regain control of the Burma Road, the six divisions of the Chinese Expeditionary Forces in India and the British and Indian forces jointly launched a counterattack against the Japanese army in northern Myanmar in late October 1943, and achieved initial results. On April 17, the following year, the Chinese Expeditionary Force carried out a counter-attack plan for crossing the river. ==Battles in Battle of Northern Burma and Western Yunnan==