Second Sino-Japanese War

Beginning in 1937, but merging into World War Two in the Pacific ending in 1941, the Second Sino-Japanese War was a period of much-increased combat, beyond the fighting at the borders with Manchuria (Manchukuo) and Korea. It was complicated by varying levels of civil war among Chinese factions, especially the Kuomintang under Chiang Kai-shek and the Communists under Mao Zedong, and lesser involvement by regional warlords. This war is differentiated from the First Sino-Japanese War of 1894-1895.

The war built on earlier conflicts in Manchuria:

Without the resources of Manchuria, China could not become a major military-industrial power. The Imperial Army's monopoly of the abundant coal, iron ore, gold reserves, and other riches of the North, and their obvious determination to hold on to them, presented Chiang with a problem that by 1937 he knew could only be resolved by war.

...Already in 1933, the world had seen Yosuke Matsuoka lead Japan defiantly from the floor of the League of Nations rather than obey its resolution that Japan should give up this crucial economic zone.

The main war has been broken into three periods, although periods of tension preceded it:

• First Period: 7 July 1937 (Battle of Lugou Bridge, also called the Marco Polo Bridge Incident) - 25 October 1938 (Fall of Hankou). "The Chinese army would put up token fights to delay Japanese advance to northeastern cities, to allow the home front, along with its professionals and key industries, to retreat further west into Chongqing to build up military strength." It traded "space for time" ( 以空间换取时间 )
• Second Period: 25 October 1938 (Fall of Hankou) - July, 1944. "During the second period, the Chinese army adopted the concept of "magnetic warfare"," using tactical and operational art to draw the Japanese into ambushes and encirclements. "The most prominent example of this tactic is the successful defense of Changsha (长沙) numerous times."
• Third Period: July 1944 - 15 August 1945. This period employs general full frontal counter-offensive. As of mid 1945, all sides expected the war to continue for at least another year. However it was suddenly ended by the capitulation of Japan to the allies on August 14, 1945. The Japanese troops in China formally surrendered on September 9, 1945 and by the provisions of the Cairo Conference of 1943 the lands of Manchuria, Taiwan and the Pescadores Islands reverted to China.

Early Japanese expansion

Emperor Hirohito wanted bases in North China for the Strike South. Since March 1935, Major General Rensuke Isogai, one of the Eleven Reliables, had been negotiating with Chiang for what the Japanese called neutralization, and what others would call Japanese sovereignty over north China.

Interactions with the U.S.

Following the Marco Polo Bridge Incident, Japan began a prolonged war against China resulting in invasions along the southern coast. Shanghai was attacked and severely devastated. In December, Japanese forces invaded the Chinese capital at Nanking; as a matter of intimidation or poor discipline, the Japanese troops' conduct led it to be called the Rape of Nanking.

In response to this aggression against China, as well as the aggressions of Italy against Ethiopia, the aggressive expansion on Nazi Germany in central Europe), and Italy's and Germany's support of Franco's Falange in the Spanish Civil War, U.S. President Franklin D. Roosevelt gave a speech in which he urge a policy of moral and economic quarantine against these belligerent nations. It was one of Roosevelt's few foreign policy speeches during the Great Depression and was not well received by the American public. Roosevelt retracted the statements. Nonetheless, to the Japanese the reverse looked like U.S. weakness. This belief was reinforced in December when Japanese bombers sank the USS Panay and three other U.S. vessels on the Yangtze River. Because of poor American response to his Quarantine speech, while the U.S. had gone to war over such incidents in the past, Roosevelt accepted a weak Japanese apology and a $2M indemnity.