Led by Mao Zedong and fortified by several former GMD military units whose commanders defected to the communists, this rural base developed into the Jiangxi Soviet Republic, whose military forces numbered 200,000 by 1933. Chinese communists also mounted several further urban and rural insurrections, and Jiang regarded them as the greatest threat to his government, more serious than even the Japanese troops who in 1932 established the client state of Manzhouguo in Manchuria and who constantly sought to enhance Japan's influence in North China. Between 1930 and 1934 Jiang waged annual campaigns against the Ruijin base in Jiangxi, in the last of which he succeeded in forcing communist supporters, in the famous Long March, to retreat 6,000 miles to the remote northwestern province of Shaanxi.
During 1935–1936 Jiang ordered troops commanded by his loyal ally, Manchurian warlord Zhang Xueliang, to attack and, he hoped, eliminate the few thousand remaining communists. The soldiers rejected his orders, arguing that all Chinese should unite to fight the Japanese, not each other. In the December 1936 Xi'an Incident, Zhang kidnapped Jiang and forced him to form a united anti-Japanese front with the communists. The GMD-CCP relationship remained strained, as communists developed their own military forces, the Eighth Route Army, commanded by Zhu De, and the New Fourth Army under Lin Biao, and retained control of northern Shaanxi.
The following year, a minor clash between Chinese and Japanese troops at the Lugouqiao Marco Polo Bridge, near Beijing in Hebei province, quickly escalated into full-scale warfare between the two countries. Over the following eighteen months, Jiang gradually retreated to Chongqing in the far southwestern province of Sichuan, abandoning northern and eastern China to protracted Japanese occupation. The communists controlled northwestern China. For three months in late 1940, the communists launched the Hundred Regiments campaign against Japan, but their eventual defeat by the better-equipped Japanese convinced them to switch to tactics of establishing guerrilla bases behind Japanese lines in northern and central China. This policy provoked ferocious Japanese reprisals against both the communists and the civilian population, but it proved effective in disrupting Japanese control and in enhancing the communists' reputation as dedicated opponents of Japanese rule and their postwar political position. It did not suffice, however, to defeat Japanese rule.
By 1940 Mao was already making plans for a postwar communist government of China. By this time, both sides anticipated a fierce struggle for power and sought to position themselves advantageously for it. In late 1941 GMD forces attacked and defeated the communist New Fourth Army in the lower Changjiang (Yangtze) Valley, an episode marking the fundamental breakdown of CCP-GMD collaboration, although an uneasy alliance continued until 1944. GMD forces possessed superior equipment and funding, but Jiang's abandonment of much of China to Japanese rule and his reliance on a protracted strategy of attrition, together with the corruption that characterized many top officials of his regime, eroded his hold on popular loyalties. Communist morale was high. Their idealistic rhetoric, the Spartan living conditions at their Yan'an base in Shaanxi, their attractive and charismatic leaders, and their dangerous though small-scale partisan operations all caught the popular imagination and impressed many visiting Western journalists and officials.
The war ended in August 1945 with Japanese occupation forces still in place throughout China. CCP membership had reached 1.2 million people, plus military forces of 900,000, and the communists controlled an area whose population numbered 90 million. Despite Jiang's objections, Russian forces entering Manchuria facilitated the surrender of Japanese forces and equipment to communist units. U.S. leaders, especially Ambassador Patrick J. Hurley in late 1945, sought to strengthen Jiang's regime, to promote reform from within, and to encourage Nationalist-communist reconciliation and the formation of a coalition government in which communists would have some influence, albeit as junior partners.
The most sustained such effort was the thirteen-month (December 1945–January 1947) mission to China of former U.S. Army chief of staff General George C. Marshall, who in January 1946 arranged a temporary cease-fire in the developing civil war, broken later that spring when, as Soviet units withdrew, GMD forces attacked Chinest communist troops in Manchuria, winning control of that region in late May. That same month the communists rechristened their military forces the People's Liberation Army (PLA). It proved impossible to devise any further agreements acceptable to both sides.
Full-scale civil war resumed on 26 June 1946 when Nationalist units launched an offensive against communist-held areas in the Hubei and Henan provinces. The United States continued to provide massive loans and quantities of military hardware to the GMD but prudently refused to commit American troops. As the Cold War rapidly developed, Soviet and American officials clearly backed different parties in the evolving Chinese Civil War, but neither was prepared to run great risks to assist its favored candidate.
By 1947, as inflation and corruption both ran rampant, Chinese businessmen and the middle class began to desert the GMD, and many fled overseas. As they had against the Japanese, the communists frequently employed guerrilla tactics against Nationalist forces. Their introduction of land reform persuaded many peasants to support them. These tactics supplemented the full-scale military campaigns that they soon became sufficiently strong to launch. In mid-May 1947, Lin and the New Fourth Army opened a major offensive in northeastern China, and six weeks later another large army commanded by Liu Bocheng moved southwest across the Huanghe River, known to Westerners as the Yellow River, into Shandong province. In September 1948 Lin began a massive campaign in Manchuria, capturing Shenyang in Liaoniang province in November, soon after 300,000 GMD troops surrendered to him. In north-central China, the communist Huai River campaign ended victoriously on 10 January 1949 after PLA troops surrounded sixty-six regiments—one-third of the existing GMD military forces. In January 1949 the GMD government fled to Taiwan, and that same month Beijing, China's symbolic capital, fell to Lin's troops, followed by the southern city of Guangzhou (Canton) in Guangdong the following October, as communist forces gradually consolidated their hold over the entire country. On 1 October 1949 Mao proclaimed the new People's Republic of China (PRC).
The Chinese Civil War and American support of the GMD government, which even after its move to Taiwan continued until the 1970s, left a lasting legacy of distrust and suspicion that divided the United States and Mainland China for several decades. American officials viewed the establishment in China of a communist government sympathetic to the Soviet Union as a major Cold War defeat, a perception enhanced by China's November 1950 intervention in the Korean War. For at least two decades, Chinese leaders in turn regarded the United States as their country's most significant international adversary, a perspective that only began to change after President Richard Nixon moved to reopen relations with China in the early 1970s.
Eastman, Lloyd E., ed. The Nationalist Era in China, 1927–1949. Cambridge: Harvard University Press, 1991.; Fairbank, John K., and Albert Feuerwerker, eds. The Cambridge History of China, Vol. 13, Republican China 1912–1949, Part 2. Cambridge: Cambridge University Press, 1986.; Liu, F. F. The Military History of Modern China, 1924–1949. Princeton, NJ: Princeton University Press, 1956.; Westad, Odd Arne. Cold War and Revolution: Soviet-American Rivalry and the Origins of the Chinese Civil War, 1944–1946. New York: Columbia University Press, 1993.; Westad, Odd Arne. Decisive Encounters: The Chinese Civil War, 1946–1950. Stanford, CA: Stanford University Press, 2003.