After Wang was defeated, Peng briefly rejoined Chiang Kai-shek's forces before joining the Chinese Communist Party (CCP), allying himself with Mao Zedong and Zhu De.

The Hundred Regiments Offensive was modestly successful, but political disputes within the Communist Party led to Peng being recalled to Yan'an, and he spent the rest of the war without an active command.

[14] Political scientist Jürgen Domes wrote that like many other young men at the time, Peng's social consciousness was awakened by their experience of impoverishment and sharpened by the disappointment they felt with the Kuomintang (KMT) for not completely following through with its revolution after the Qing dynasty was overthrown.

Communist-leaning cadres of the Kuomintang were some of the most ardent advocates of the KMT party platform, which had called for national sovereignty, eradication of warlordism, a welfare state, and equal distribution of land.

During the fourth encirclement campaign involving 400,000 NRA soldiers, Peng successfully defeated an elite enemy division in Chiaohu and forayed into Fujian province, capturing a large amount of ammunition.

The communist military leaders, including Peng and Zhu De, prepared largely static defenses, a strategy supported by the internationalists, the returned "students", and German advisor Otto Braun.

At the August 20, 1937 Luochuan Conference (洛川会议), Mao believed that the united front should be used as a feint by giving token resistance to the Japanese but saving the strength of the Red Army for the eventual confrontation with the Kuomintang.

From August 20 to October 5, 1940, communist forces destroyed large numbers of bridges, tunnels, and railroad tracks in Japanese-occupied China and inflicted relatively heavy Japanese casualties.

[30] After being recalled to Yan'an, Peng was subjected to a political indoctrination campaign in which he was criticized as an "empiricist" for his good relations with the Comintern and survived professionally only through an unconditional conversion to Mao's leadership.

"[38] On May 4 Peng's forces attacked an isolated supply depot in northeastern Shaanxi, arrested its commander, and captured food reserves, 40,000 army uniforms, and a collection of arms that included over a million pieces of artillery.

Peng launched a final Fifth Phase Campaign from April 22 to June 10 to retake Seoul with 548,000 Chinese troops,[50] but it failed, and the Korean War came to a standstill just north the 38th parallel.

After the government representatives emphasized their inability to meet the demands of the war, Peng, in an angry outburst, shouted, "You have this and that problem.... You should go to the front and see with your own eyes what food and clothing the soldiers have!

[69] During the late 1950s, Peng developed a personal dislike for Mao's efforts to promote his own image in Chinese popular culture as a perfect hero singularly responsible for the communist victories of his time.

Liu Shaoqi, Deng Xiaoping, Peng Zhen, and most other senior CCP members present quickly agreed, and it was removed from the final version of the 1956 Party Constitution.

From April 24 to June 13, 1959, Peng went on a "military goodwill tour" across the communist world and visited Poland, East Germany, Czechoslovakia, Hungary, Romania, Bulgaria, Albania, the Soviet Union, and Mongolia.

[78] Peng was still in command of the PLA when Mao ordered the shelling of Kinmen (Quemoy) and Matsu, islands off the coast of Fujian that were still held by the Kuomintang, in the late summer and autumn of 1958.

Peng had quietly opposed the operation from the beginning and gradually began to end hostilities after the PLA had encountered serious difficulties by announcing a series of intermittent ceasefires and eventually halting the campaign in late October.

Peng's position was not directly affected, but his personal prestige suffered, and the practical effects of his efforts to modernize China's armed forces were called into question within the PLA.

Mao's theories on mass collectivization became the basis of the Great Leap Forward,[81] a national economic plan that began in 1958 which caused a man-made famine across the country that lasted for several years.

[82] From October–December 1958, the economic system in the countryside broke down as farmers refused to go to work in the fields, raided government granaries for food, and in Guangdong, Hubei, Hunan, Jiangxi, Sichuan, and Qinghai, rebelled.

As part of the Great Leap Forward, Mao ordered the formation of a national militia that was controlled by Party members and independent of the PLA, eventually training and arming tens of millions of civilians.

On the same tour Peng heard complaints that household utensils were being melted down for "steel", and that houses and orchards were cut and torn down in order to provide fuel for the backyard furnaces.

In a subsequent tour through his native province of Hunan, later in 1958, Peng observed the same problems associated everywhere with the Great Leap Forward: serious food shortages; hungry children and babies; elders who expressed bitterness and anger; and arrogant, boasting Party cadres who administered local economic reforms.

[88] Peng participated in group meetings in the early portion of the conference, gaining consensus among his peers for criticizing the widespread practice of inaccurately reporting agricultural statistics, and emphasizing that "everybody had a share of responsibility, including Comrade Mao Zedong".

On July 21, Zhang Wentian gave an independent, supplementary speech attacking Mao's policies, and the same day a majority of delegates expressed their approval of Peng's letter, making it an official conference document.

He attacked Peng and those who shared his political opinions as "imperialists" "bourgeoisie", and "rightists", and associated their positions with other Communist leaders who had led failed oppositions to Mao's leadership, including Li Lisan, Wang Ming, Gao Gang, and Rao Shushi.

Lin reversed Peng's reforms,[95] abolished all signs and privileges of rank, purged officers considered sympathetic to the Soviets, directed soldiers to part-time work as industrial and agricultural laborers, and indoctrinated the armed forces in Mao Zedong Thought.

On June 16, 1962, Peng submitted a document, his "Letter of 80,000 Words," to Mao and the Politburo, which gave a full account of his life, admitted to several "mistakes," defended himself against most of the accusations made against him at the Lushan Conference, requested to be readmitted to decision-making government bodies, and sharply criticized the economic policies of the Great Leap Forward.

Peng worked energetically until August 1966, when the beginning of the Cultural Revolution had him recalled to Chengdu, and the first Red Guards began patrolling the streets and violently attacking their perceived enemies.

[106] In January 1967, Peng was taken to his first "struggle session" in which he was paraded in chains before several thousand jeering Red Guards, wearing a large paper dunce cap and with a wooden board hung from his neck on which his "crimes" were written.