The Second United Front 1937 to 1945, including the Xi'an Incident, the New Fourth Army Incident, and the deterioration of KMT-CCP relations during the war with Japan

What this dot point is asking

NESA expects you to explain how the Xi'an Incident forced the Second United Front, what the alliance meant operationally and politically, how the New Fourth Army Incident showed its breakdown, and how the CCP used the wartime years to grow. Strong answers integrate KMT calculation, CCP strategy, Stalin's directives, and the New Fourth Army Incident.

The answer

The Xi'an Incident

By late 1936 Mao's CCP had reached Yan'an after the Long March. Chiang had moved Zhang Xueliang's Manchurian Northeastern Army (around 130,000 men) to Shaanxi to lead a Sixth Encirclement Campaign. Zhang's men resented fighting Communists rather than reclaiming their Japanese-occupied homeland. CCP propaganda (the "August First Declaration" of 1935) explicitly courted them.

Zhang met Zhou Enlai secretly in April 1936 and agreed in principle to a cease-fire. Chiang flew to Xi'an on 4 December 1936 to override Zhang's resistance and force a renewed campaign. On 12 December 1936 Zhang's troops surrounded Chiang's compound at Huaqing, captured the Generalissimo, and demanded a cease-fire with the CCP and a war of national resistance.

The Comintern wanted Chiang alive. Stalin saw a unified anti-Japanese front as essential to relieve pressure on the Soviet Far East. He ordered the CCP to negotiate Chiang's release. Zhou Enlai flew to Xi'an. After thirteen days of negotiation Chiang was released on 25 December 1936; the agreement was nominally oral but extensive. Zhang Xueliang voluntarily returned to Nanjing with Chiang as a gesture of good faith and spent the next 55 years under house arrest (released 1991, in Taiwan).

Formal United Front terms

The CCP and KMT signed the formal Second United Front agreement in September 1937 after war with Japan had begun.

CCP concessions:

• The Chinese Soviet Republic became the Shaan-Gan-Ning Border Region under KMT nominal authority.
• The Red Army was redesignated the National Revolutionary Army's Eighth Route Army (around 45,000 men) and New Fourth Army (around 12,000 men in central China).
• The CCP nominally abandoned land confiscation, replaced by rent reduction.

KMT concessions:

• Legal recognition of the CCP.
• Cessation of the "bandit suppression" campaigns.
• Modest subsidies to the Eighth Route Army.

Operational cooperation

Joint operations were limited. The Battle of Pingxingguan (25 September 1937), where Lin Biao's 115th Division ambushed a Japanese convoy in Shanxi and killed around 1,000 Japanese, was the showpiece of CCP-KMT military cooperation. CCP propaganda from 1945 onward used Pingxingguan to claim the CCP had been the main resistance force.

The Hundred Regiments Offensive (August-December 1940) was the only major CCP conventional operation of the war. Around 400,000 troops under Peng Dehuai attacked Japanese railways and strongpoints in north China. CCP claims of around 40,000 Japanese casualties were inflated; real losses were smaller, and Japanese punitive sweeps in 1941-1942 cost the CCP perhaps 100,000 dead.

Political competition

Most cooperation was political theatre. Both parties used the Front to compete for legitimacy with intellectuals, students, and overseas Chinese. The CCP's Yan'an became a destination for thousands of Chinese youth and Western journalists. KMT Chongqing was simultaneously the official wartime capital and the focus of corruption charges.

KMT pressure on the CCP

From 1939 Chiang tightened the screws. The KMT instituted an economic blockade of the Shaan-Gan-Ning Border Region from late 1939, with around 400,000 troops cordoning the area. The CCP responded with the "production movement" (1942 onward), including the Nanniwan reclamation project, to achieve self-sufficiency.

The Communications Conference in Nanyue (January 1940) produced KMT plans to limit CCP base-area expansion. CCP plans, in turn, accelerated expansion through "anti-Japanese democratic regimes" in counties on the Yellow Plain.

The New Fourth Army Incident

The New Fourth Army operated in central China south of the Yangtze. The KMT high command ordered it north of the Yellow River in 1940; the CCP delayed compliance. On 5 January 1941, KMT forces under General Gu Zhutong attacked the New Fourth Army headquarters column of around 9,000 men in southern Anhui. Fighting lasted until 13 January.

Around 9,000 CCP troops were killed, wounded, or captured. Commander Ye Ting was captured and imprisoned (released 1946, killed in a plane crash). Political commissar Xiang Ying was killed by a deserter. The KMT formally dissolved the New Fourth Army; the CCP recreated it within weeks under Chen Yi and Liu Shaoqi and continued operating.

Diplomatic protests followed. The United States, in particular, pressured Chiang to stop attacking his nominal ally. The CCP recovered politically.

Yan'an Rectification

From 1942 to 1944 Mao consolidated his ideological control over the CCP through the "Yan'an Rectification Movement" (Zhengfeng). Studied texts included Mao's own writings ("Reform Our Study," "Oppose Stereotyped Party Writing"). The movement crushed Wang Ming's Comintern faction and Kang Sheng's secret-police operations against alleged spies escalated; perhaps several thousand were killed or driven to suicide.

The Seventh Party Congress (April-June 1945) formally enshrined "Mao Zedong Thought" as Party doctrine. Mao became Chairman of the Politburo and of the Central Committee; Liu Shaoqi became second-ranking.

The Front's formal end

The Second United Front formally lasted until the Japanese surrender. Real cooperation had ended at the New Fourth Army Incident. Marshall Mission talks (December 1945 to January 1947) tried to revive a national coalition after the war but failed.

Timeline 1936-1945

Historiography

Lyman Van Slyke (Enemies and Friends: The United Front in Chinese Communist History, 1967) is the standard analytical study.

Lloyd Eastman (Seeds of Destruction: Nationalist China in War and Revolution, 1937-1949, 1984) frames the wartime erosion of the KMT.

Odd Arne Westad (Decisive Encounters: The Chinese Civil War 1946-1950, 2003) treats the wartime years as setting the conditions for the civil war.

Chen Yung-fa (Making Revolution, 1986) is rigorous on CCP base-area work.

Rana Mitter (China's War with Japan, 2013) is balanced on KMT and CCP roles.

How to read a source on this topic

Sources include the Xi'an Incident broadcasts, the September 1937 manifesto, Mao's "On New Democracy" (January 1940), KMT denunciations of the New Fourth Army, and Stilwell's diaries. Three reading habits.

First, separate the rhetoric from the operations. Both sides spoke of unity while planning each other's containment.

Second, follow the Comintern angle on Xi'an. Stalin's veto of executing Chiang is one of the most consequential foreign interventions in modern Chinese history.

Third, watch what the CCP did with the legitimacy. The Front gave the CCP eight years to grow without KMT military pressure. The 1937 baseline (40,000 members, 92,000 troops) and the 1945 figure (1.2 million members, 1.2 million regulars, 2.6 million militia) tell the story.

Common exam traps

Treating the Front as cooperation throughout. From 1939 it was largely fictional; after January 1941 it was a formality.

Confusing the First and Second Fronts. First (1924-1927) was inside the KMT; Second (1937-1945) was a parallel alliance. First was destroyed by Chiang; Second was eroded by both sides and ended at the Japanese surrender.

Ignoring Stalin. Stalin's intervention saved Chiang's life in December 1936. Without that, the timeline of Chinese politics from 1936 onward is unrecognisable.

In one sentence

The Second United Front, forced on Chiang by the Xi'an Incident (December 1936) and formalised in September 1937, gave the CCP legal status and eight years of breathing room in which to grow from 40,000 members and 92,000 troops to 1.2 million members and 1.2 million regulars; the New Fourth Army Incident (January 1941) ended operational cooperation, but the formal alliance lasted to the Japanese surrender of September 1945.