Editing Chinese Civil War (section)

===Negotiations and the Xi'an Incident===
{{Main|Xi'an Incident}}
In late 1935, Chiang Kai-shek started secret negotiations with the Soviet Union in the hopes of gaining material assistance if war broke out between China and Japan. As a precondition for an agreement, the Soviets wanted Chiang to negotiate a ceasefire with the CCP.{{sfn|Yang|2020|p=62}} Although reluctant to engage with a group he saw as a rebels, Chiang cautiously sought to establish contact with the CCP.{{sfn|Yang|2020|p=63}}{{sfn|Itoh|2016|pp=124-125}} The CCP Central Committee told them that the CCP was interested in a united anti-Japanese army under a government of national defense.{{sfn|Pantsov|2023|pp=230-231}} Given the wide gap between the CCP and KMT's conditions, further negotiations did not take place during the first half of 1936.{{sfn|Yang|2020|p=63}} 

Meanwhile, the CCP opened up separate negotiations with the Nationalist forces besieging them in northwest China. They managed to sign secret ceasefire agreements with [[Zhang Xueliang]], leader of the [[Northeastern Army]], and [[Yang Hucheng]], leader of the Northwestern Army.{{sfn|van de Ven|2003|p=179}} These generals were frustrated that Chiang' was prioritizing Civil War over resistance to Japan.{{sfn|Coble|1991|pp=224-225}}{{sfn|Itoh|2016|p=108}} Yan Xishan, another neighboring warlord, also signed a secret agreement with the Communists, although he was not as closely aligned with them as Zhang or Yang.{{sfn|Gillin|1967|p=232}} The members of this northwestern alliance were united by their desire to resist Japan, but they differed over the details of how this could best be accomplished.{{sfn|van de Ven|2003|p=179}} The Communists supported a plan to use Soviet support to take over [[Shaanxi]], [[Gansu]], [[Ningxia]], [[Qinghai]], and [[Xinjiang]] and turn northwest China into a base under Zhang's command to resist Japan and oppose Chiang.{{sfn|Yang|2020|p=64}} Zhang, Yang, and Yan were still committed to convincing Chiang to lead the anti-Japanese resistance.{{sfn|van de Ven|2003|p=179}} As they continued to negotiate, they kept their alliance secret and even staged fake military battles to allay the suspicions of the Nanjing government.{{sfn|Barnouin|Yu|2006|p=65}}{{sfn|van de Ven|2003|p=179}} 

Negotiations between Chiang and the CCP began in earnest in late 1936.{{sfn|Sheng|1992|p=158}} Chiang continued to try to resolve the civil war militarily; he continued to consider a negotiated settlement with the CCP to be a last resort.{{sfn|Chen|2024|pp=161-162}} He was encouraged by the results of the Ningxia campaign in mid-to-late October. In that campaign, the Second and Fourth Corps of the Red Army marched north to pick up supplies dropped in Mongolia by the Soviet Union, but found themselves trapped on the wrong side of the Yellow River.{{sfn|Yang|2020|p=65}} They were cut to pieces by the [[Hui people|Hui]] cavalry allied with the Nationalists.{{sfn|Watt|2014|pp=111-112}} Chiang began making preparations for a sixth encirclement campaign, and instructed Zhang and Yang to participate.{{sfn|Itoh|2016|pp=129-130}} In early November, Chen Lifu presented Pan Hannian with a set of extremely harsh conditions for a deal.{{efn|The terms called for, among other things, reducing the Red Army to 3,000 men and sending all of its senior officers into exile.{{sfn|Peng|2023|p=476}}{{sfn|Sheng|1992|p=163}}}} Pan balked, calling them "conditions for surrender".{{sfn|Chen|2024|p=161}} In late November, Chiang ordered the Northeastern Army and forces from the central Nationalist Army, [[Hu Zongnan]]'s Right Route Army, to attack towards the Communist capital at [[Zhidan County|Bao'an]]. At the resulting Battle of Shanchengbao, the Northeastern Army withheld most of its forces from the attack. This allowed the Red Army to ambush and nearly wipe out Hu's 78th regiment.{{sfn|Dillon|2020|p=102}}{{sfn|Yang|1990|p=223}} This reversed the diplomatic situation: Chen Lifu moderated his conditions, but the CCP recalled Pan Hannian from Nanjing on December 10.{{sfn|Dillon|2020|pp=101-102}}{{sfn|Peng|2023|pp=476-477}}

In late 1936, Zhang Xueliang decided that his repeated attempts to persuade Chiang to create a united front with the Communists were not going to be enough. To Zhang, Chiang appeared dead-set on continuing the Civil War even as the threat of Japanese invasion loomed ever larger. Following Yang Hucheng's advice, he decided to resort to drastic measures.{{sfn|Pantsov|2023|pp=241-242}}{{sfn|Pantsov|2012|p=302}} On 12 December 1936, the disgruntled Zhang and Yang conspired to kidnap Chiang and force him into a truce with the CCP. The incident became known as the Xi'an Incident.<ref name="Ye2003">Ye, Zhaoyan Ye, Berry, Michael. (2003). ''Nanjing 1937: A Love Story''. Columbia University Press. {{ISBN|0-231-12754-5}}.</ref> Both parties suspended fighting to form a Second United Front to focus their energies and fight the Japanese.<ref name="Ye2003" />