The war is generally divided into two phases with an interlude: from August 1927 to 1937, the First United Front alliance of the KMT and CCP collapsed during the Northern Expedition, and the Nationalists controlled most of China.From 1937 to 1945, hostilities were mostly put on hold as the Second United Front fought the Japanese invasion of China with eventual help from the Allies of World War II, although armed clashes between the groups remained common.[13] Following the collapse of the Qing dynasty and the 1911 Revolution, Sun Yat-sen assumed the presidency of the newly formed Republic of China, and was shortly thereafter succeeded by Yuan Shikai.[21] On 7 April, Chiang and several other KMT leaders held a meeting, during which they proposed that Communist activities were socially and economically disruptive and had to be undone for the Nationalist revolution to proceed.[32] Unlike previous campaigns in which they penetrated deeply in a single strike, this time the KMT troops patiently built blockhouses, each separated by about eight kilometres (five miles), to surround the Communist areas and cut off their supplies and food sources.[31] In October 1934, the CCP took advantage of gaps in the ring of blockhouses (manned by the forces of a warlord ally of Chiang Kai-shek's, rather than regular KMT troops) and broke out of the encirclement.The KMT enlisted 300 "Khampa bandits" into its Consolatory Commission military in Sichuan, where they were part of the effort of the central government to penetrate and destabilize local Han warlords such as Liu Wenhui.Chiang demanded in December 1940 that the CCP's New Fourth Army evacuate Anhui and Jiangsu Provinces, due to its provocation and harassment of KMT forces in this area.The Soviet Union, allied more closely with the CCP, sent an imperative telegram to Mao in 1941, warning that civil war would also make the situation easier for the Japanese military.[41]: 54 In the last month of World War II in East Asia, Soviet forces launched the huge Manchurian Strategic Offensive Operation against the Japanese Kwantung Army in Manchuria and along the Chinese-Mongolian border.[48] This operation destroyed the Kwantung Army in just three weeks and left the USSR occupying all of Manchuria by the end of the war in a total power vacuum of local Chinese forces.However, the Soviets refused permission for the Nationalist troops to traverse its territory and spent the extra time systematically dismantling the extensive Manchurian industrial base (worth up to $2 billion) and shipping it back to their war-ravaged country.These favorable conditions also facilitated many changes inside the Communist leadership: the more radical hard-line faction who wanted a complete military take-over of China finally gained the upper hand and defeated the careful opportunists.We therefore had to take the unusual step of using the enemy as a garrison until we could airlift Chinese National troops to South China and send Marines to guard the seaports.With KMT efforts for an all-out offensive failing, the Nationalists changed strategy from broad assaults to concentrating on key targets, including Communist-controlled areas in Shandong and Shaanxi.[66] The capture of large KMT units provided the CCP with the tanks, heavy artillery and other combined-arms assets needed to execute offensive operations south of the Great Wall.[54][41]: 58 Stalin initially favored a coalition government in postwar China, and tried to persuade Mao to stop the CCP from crossing the Yangtze and attacking the KMT positions south of the river.Chiang Kai-shek and approximately two million Nationalist soldiers retreated from mainland China to the island of Taiwan in December after the PLA advanced into Sichuan province.US President Harry S. Truman announced on 5 January 1950 that the United States would not engage in any dispute involving the Taiwan Strait, and that he would not intervene in the event of an attack by the PRC.[76] Truman, seeking to exploit the possibility of a Titoist-style Sino-Soviet split, announced in his United States Policy toward Formosa that the US would obey the Cairo Declaration's designation of Taiwan as Chinese territory and would not assist the Nationalists.This led to changing political climate in the US, and President Truman ordered the United States Seventh Fleet to sail to the Taiwan Strait as part of the containment policy against potential Communist advance.Though the US rejected Chiang Kai-shek's proposal to bomb mainland China artillery batteries, it quickly moved to supply fighter jets and anti-aircraft missiles to the ROC.[93][94][95][96] As a result, the PLA announced four days of unprecedented military live-fire drills,[97] in six zones that encircle the island on the busiest international waterways and aviation routes.[98] In response to the announcement, ROC officials complained that the PRC's live-fire drills were an invasion of Taiwan's territorial space and a direct challenge to free air and sea navigation.[102] Under the new ROC president Lee Teng-hui, the Temporary Provisions Effective During the Period of Communist Rebellion was renounced in May 1991, thus ending the chances of the Kuomintang's quest to retake the mainland.With the election of pro-mainland President Ma Ying-jeou (KMT) in 2008, significant warming of relations resumed between Taipei and Beijing, with high-level exchanges between the semi-official diplomatic organizations of both states such as the Chen-Chiang summit series.He believed that the Nationalists had displayed both political inadequacy as well as "the grossest incompetence ever experienced by any military command," and that the Communists "did not create this condition", but skillfully exploited the opportunity it provided.Apart from that, the CCP had mastered the manipulation of local politics to their benefit; this was also derived from their propaganda skills that had also been decentralised successfully by portraying their opponents as "enemies of all groups of Chinese" and itself as "defenders of the nation" and people (given the backdrop of the war with Japan).Historians such as Jay Taylor, Robert Cowley, and Anne W. Carroll argue that the Nationalists' failure was largely caused by external reasons outside of the KMT's control, most notably the refusal of the Truman administration to support Chiang with the withdrawal of aid, the US armed embargo, the failed pursuit of a détente between the Nationalists and the communists, and the USSR's consistent support of the CCP in the Chinese Civil War.[128] Between 1931 and 1934 in the Jiangxi–Fujian Soviet, the communist authorities engaged in a widespread campaign of violence against civilians to ensure compliance with its policies and to stop defection to the advancing KMT, including mass executions, land confiscation and forced labor.
Chiang Kai-shek and Mao Zedong met in Chongqing in 1945.