Hundred Regiments Offensive

The Hundred Regiments Offensive (20 August–5 December 1940) was a major campaign of the Communist Party of China's National Revolutionary Army divisions commanded by Peng Dehuai against the Imperial Japanese Army in Central China.

Background
In 1939-1940, the Japanese occupiers launched more than 109 small campaigns involving around 1,000 combatants each and 10 large campaigns of 10,000 men each to wipe out Communist guerrillas in the Hebei and Shandong plains. In addition, Wang Jingwei′s anti-Communist puppet government had its offensive against the CCP guerrillas.

There was also a general sentiment among the anti-Japanese resistance forces—particularly in the Kuomintang—that the CCP was not contributing enough to the war effort, and that they were only interested in expanding their power base. It was out of these circumstances that the CCP planned to stage a great offensive to prove that they were helping the war effort and to mend KMT-CCP relations.

The battle
The Japanese North China Area Army estimated the strength of communist regulars to be about 88,000 in December 1939. Two years later, they revised the estimate to 140,000. On the eve of the battle, the Communist forces grew to 400,000 men strong, in 115 regiments. The extraordinary success and expansion of the 8th Route Army against the Japanese had Zhu De and the rest of the military leadership hoping that they could engage the Japanese army and win.

By 1940, growth was so impressive that Zhu De ordered a coordinated offensive by most of the communist regulars (46 regiments from the 115th Division, 47 from the 129th, and 22 from the 120th) against the Japanese-held cities and the railway lines linking them. From 20 August-10 September, communist forces attacked the railway line that separated the communist base areas, chiefly those from Dezhou to Shijiazhuang in Hebei, Shijiazhuang to Taiyuan in central Shanxi, and Taiyuan to Datong in northern Shanxi.

They succeeded in blowing up bridges and tunnels and ripping up track, and went on for the rest of September to attack Japanese garrisons frontally. About 600 mi of railways were destroyed, and the Jingxing coal mine—which was important to the Japanese war industry—was rendered inoperative for six months. It was the greatest victory the CCP fought and won during the war.

However, from October to December, the Japanese responded in force, reasserting control of railway lines and conducting aggressive "mopping up operations" in the rural areas around them.

Aftermath
When General Yasuji Okamura took command of the North China Area Army in the summer, the new approach was "Three All" meaning "kill all, burn all, and destroy all" in those areas containing Anti-Japanese forces.

Peng was criticized by Mao for revealing the number of the Communist forces to the Kuomintang. Thus, the Hundred Regiments Offensive became the last of the two major Communist frontal engagements against the Japanese during the war. During the Cultural Revolution, Peng's action was one of the pretexts used by the Gang of Four that led to his downfall. The consensus in China after Cultural Revolution is generally in support of the battle.