Second Sino-Japanese War (jul 7, 1937 – sep 9, 1945)

Description:

The Second Sino-Japanese War was a military conflict fought primarily between the Republic of China and the Empire of Japan from July 7, 1937, to September 2, 1945. It began with the Marco Polo Bridge Incident in 1937 in which a dispute between Japanese and Chinese troops escalated into a battle.
During the Marco Polo Bridge Incident Japanese military demanded permission to enter the Chinese city of Wanping to search for a missing soldier. The Chinese refused. Later in the night, a unit of Japanese infantry attempted to breach Wanping's walled defences and were repulsed. An ultimatum by the Japanese was issued before they would declare war. The Chinese still refused.
Although Private Shimura returned to his unit, by this point both sides were mobilising, with the Japanese deploying reinforcements and surrounding Wanping. The conflict then escalated further into a full-scale war.
China fought Japan, with aid from the Soviet Union and the United States. After the Japanese attack on Pearl Harbor in 1941, the war merged with other conflicts of World War II as a major sector known as the China Burma India Theater.