Invasion of Manchuria The invasion of Manchuria was a conflict fought between China and Japan in the province of Manchuria in north - east China . It lasted from 1931 until 1932 and was a key event in the origins of World War II in Asia . Origins . China experienced a revolution in 1911 , in which the nationalist alliance which became the Kuomintang overthrew the Emperor , Pu Yi . After obtaining power , the Kuomintang , led by Chiang Kai - shek , turned its attention to combating the growing communist movement filtering in from the Soviet Union to the north . The operations against the communists degenerated into a stalemate which lasted deep into the 1930s . Order in China began to deteriorate as the two ideologies struggled for dominance . Manchuria was threatened by trade strangulation by the construction of a Russia n railway connecting the Pacific port of Vladivostok to Europe . Both Chinese and Japan ese trade suffered as a result . It was in this context that Japan , emerging as an expansionist power on the continent , made her move . She sought to expand her Empire and gain control of China ' s natural resources , but also ostensibly intended to bring order to a divided China and attract trade back to the region . Woo , an officer who later deserted the Imperial Japanese Army , suspected Japan had been preparing for war year s before the events in Manchuria and was unconvinced by the Japanese justification for the invasion . ( PROSE : " The Shadow of Weng - Chiang " ) The invasion . In 1931 , influenced by the Sakura Kai , the Japanese engineered a fight between the Chinese forces in the province to justify the invasion . They claimed the Chinese had attacked first . The Japanese went on to capture all of Manchuria . In 1932 ( PROSE : " Log 384 " ) the occupation was completed after the region was organised into the puppet state of Manchukuo , ruled by Pu Yi . However , as Woo later pointed out to some young Japanese officers , this did not mean and end to hostilities between Japan and China . ( PROSE : " The Shadow of Weng - Chiang " ) Aftermath . Japanese experiments . The Kwantung Army subjugated the peasant population of Manchuria and set them to work constructing the Zhong Ma fortress . Atrocities were committed to deter the peasants from attempting to escape and any who tried were immediately shot . Manchuria became a testing ground for experiments in biological warfare headed by the young Japanese military scientist Ishii Shiro . Using the peasants as test subjects , taking blood samples , dissecting people , and deliberately infecting them with bubonic plague , the Japanese sought to learn more about the human body and how they may weaponise germs . The data gathered allowed for the creation of biological weapons that the Japanese later deployed against China to devastating effect , before they surrendered to the Americans in 1945 . ( PROSE : " Log 384 " ) Further conflict . Disputes over Manchuria / Manchukuo persisted between China and Japan throughout rest of the decade . ( PROSE : " The Year of Intelligent Tigers " ) The Japanese referred to the region as Manchukuo while the Chinese continued to call it Manchuria . ( PROSE : " The Shadow of Weng - Chiang " ) Edward Grainger felt that the invasion of Manchuria demonstrated Japan ' s determination to dominate all of Asia . ( PROSE : " Log 384 " ) Greater conflict threatened to engulf the continent after Chinese and Japanese troops clashed in Shanghai in 1932 . Having gained a foothold in northern China through the invasion , the Japanese army split into two factions following disagreements about the next steps to be taken . The Kodo Ha , controlled by the Sakura Kai , demanded further expansion in Manchukuo and into China to offset strategic advantages enjoyed by the Soviet Union . The Tosei Ha , while also expansionist , advocated a more cautious approach within the political system that adhered to the formal rules of engagement . The Kodo Ha held the loyalty of local commander s in Manchukuo and used them to assassinate a number of political ministers , including prime minister s , between 1933 and 1935 . A revolt in Tokyo by the Kodo Ha ' s supporters , the Japanese First Infantry Division , in February 1936 was ultimately suppressed . The Kodo Ha held onto its control of the local Manchukuo commanders but the Tosei Ha , who viewed China as Japan ' s main enemy , held onto control of the military . In July 1937 , the Japanese engineered another fight between the Chinese forces at Marco Polo Bridge . This moved the government onto a war footing , signaling the beginning of World War II in Asia . The front lines were initially located on the frontier between Manchukuo and China , with the Japanese Twelfth Army seeking to advance south into Shangdong province and towards Shanghai , although they sought to further consolidate their hold on Manchuria first . The Japanese launched air raids against Shanghai from Manchukuo simply to prove to the Chinese population that they could . Woo sought to create a united front in Shanghai to resist the Japanese advance . In August 1937 , Hsien - Ko sought to prevent Magnus Greel ' s death so that he could be formally punished . She believed one of the consequences of her success would be the undoing of the invasion of Manchuria and the war with Japan altogether . However , her plan was thwarted by the Fourth Doctor and Romana I , and somewhat unwittingly by Sung - Chi Li , before she created a temporal paradox . ( PROSE : " The Shadow of Weng - Chiang " )