Editing Second Sino-Japanese War (section)

===Relationship between the Nationalists and the Communists===
[[File:Zhu De with NRA Emblem.jpg|thumb|upright|[[Eighth Route Army]] Commander [[Zhu De]] with a KMT "Blue Sky, White Sun" emblem cap]]

After the Mukden Incident in 1931, Chinese public opinion was strongly critical of Manchuria's leader, the "young marshal" Zhang Xueliang, for his non-resistance to the Japanese invasion, even though the Kuomintang central government was also responsible for this policy, giving Zhang an order to improvise while not offering support. After losing Manchuria to the Japanese, Zhang and his [[Fengtian clique|Northeast Army]] were given the duty of suppressing the Red Army in Shaanxi after their [[Long March]]. This resulted in great casualties for his Northeast Army, which received no support in manpower or weaponry from Chiang Kai-shek.

In the [[Xi'an Incident]] that took place on 12 December 1936, Zhang Xueliang kidnapped Chiang Kai-shek in [[Xi'an]], hoping to force an end to KMT–CCP conflict. To secure the release of Chiang, the KMT agreed to a temporary ceasefire with the Communists. On 24 December, the two parties agreed to a [[Second United Front (China)|United Front]] against Japan; this had salutary effects for the beleaguered Communists, who agreed to form the [[New Fourth Army]] and the [[8th Route Army]] under the nominal control of the NRA. In addition, [[Shaan-Gan-Ning]] and Shanxi-Chahar-Hebei border regions were created, under the control of the CCP. In Shaan-Gan-Ning, Communists in the Shaan-Gan-Ning Base Area fostered [[History of opium in China|opium production]], taxed it, and engaged in its trade—including selling to Japanese-occupied and KMT-controlled provinces.<ref name=":03">{{Cite book |last=Chun |first=Yung-fa |author-link=Chen Yung-fa |title=New Perspectives on the Chinese Revolution |date=1995 |publisher=[[Routledge]] |isbn=9781315702124 |editor-last=Saich |editor-first=Tony |location=New York |chapter=The Blooming Poppy under the Red Sun: The Yan'an Way and the Opium Trade |doi=10.4324/9781315702124 |oclc=904437646 |editor-last2=van de Ven |editor-first2=Hans |editor-link2=Hans van de Ven}}</ref><ref name=":1">{{Cite journal |last=Hevia |first=James Louis |year=2003 |title=Opium, Empire, and Modern History |url=http://muse.jhu.edu/content/crossref/journals/china_review_international/v010/10.2hevia.pdf |journal=China Review International |volume=10 |issue=2 |pages=307–326 |doi=10.1353/cri.2004.0076 |s2cid=143635262 |issn=1527-9367}}</ref> The Red Army fought alongside KMT forces during the [[Battle of Taiyuan]], and the high point of their cooperation came in 1938 during the [[Battle of Wuhan]].

The formation of a united front added to the legality of the CCP, but what kind of support the central government would provide to the communists were not settled. When compromise with the CCP failed to incentivize the Soviet Union to engage in an open conflict against Japan, the KMT withheld further support for the Communists. To strengthen their legitimacy, Communist forces actively engaged the Japanese early on. These operations weakened Japanese forces in Shanxi and other areas in the North. Mao Zedong was distrustful of Chiang Kai-shek, however, and shifted strategy to guerrilla warfare in order to preserve the CCP's military strength.<ref>{{Cite web |last1=Nobu |first1=Iwatani |title=How the War with Japan Saved the Chinese Communist Party |url=https://www.nippon.com/en/in-depth/d00722/ |website=Nippon Communications Foundation |date=27 July 2021}}</ref>

Despite Japan's steady territorial gains in northern China, the coastal regions, and the rich [[Yangtze River]] Valley in central China, the distrust between the two antagonists was scarcely veiled. The uneasy alliance began to break down by late 1938, partially due to the Communists' aggressive efforts to expand their military strength by absorbing Chinese guerrilla forces behind Japanese lines. Chinese militia who refused to switch their allegiance were often labelled "collaborators" and attacked by CCP forces. For example, the Red Army led by [[He Long]] attacked and wiped out a brigade of Chinese militia led by Zhang Yin-wu in Hebei in June 1939.{{sfn|Huang|p=259}} Starting in 1940, open conflict between Nationalists and Communists became more frequent in the occupied areas outside of Japanese control, culminating in the [[New Fourth Army Incident]] in January 1941.

Afterwards, the Second United Front completely broke down and Chinese Communists leader [[Mao Zedong]] outlined the preliminary plan for the CCP's eventual seizure of power from Chiang Kai-shek. Mao himself is quoted outlining the "721" policy, saying "We are fighting 70 percent for self development, 20 percent for compromise, and 10 percent against Japan".{{Citation needed|date=May 2024}} Mao began his final push for consolidation of CCP power under his authority, and his teachings became the central tenets of the CCP doctrine that came to be formalized as [[Mao Zedong Thought]]. The Communists also began to focus most of their energy on building up their sphere of influence wherever opportunities were presented, mainly through rural mass organizations, administrative, land and tax reform measures favouring poor peasants; while the Nationalists attempted to neutralize the spread of Communist influence by military blockade of areas controlled by CCP and fighting the Japanese at the same time.<ref name=CRISIS-TIME-MAGAZINE>{{cite magazine|title=Crisis|url=http://www.time.com/time/magazine/article/0,9171,801570-4,00.html|archive-url=https://web.archive.org/web/20071120121411/http://www.time.com/time/magazine/article/0,9171,801570-4,00.html|url-status=dead|archive-date=20 November 2007|magazine=[[Time (magazine)|Time]]|date=13 November 1944}}</ref>