During the Liberation War, the Northeast Field Army, later the Fourth Field Army, was the largest field army at that time, with the best weapons and equipment, and the strongest combat effectiveness. The reason why this unit has such a strong combat effectiveness, in addition to the proper command of generals at all levels, there is also a very important reason, that is, the Soviet Union, as well as the assistance of the DPRK.
Many people believe that during the War of Liberation, the Soviet Union's assistance to the Northeast Field Army was great, in fact, under the circumstances at that time, the Soviet Union avoided conflicts with the United States and avoided international disputes, and the assistance to Higashino was not large. On the contrary, the country is weak, and the newly restored DPRK has provided great assistance to China. The relationship between Korea and China is very special, and it has always been a vassal state of China in ancient times. After the end of the Sino-Japanese War, although Korea became a colony of the Japanese, it never gave up resistance, and many Koreans came to China, hoping that China would help Korea recover after completing the democratic revolution. Later North Korean leader Kim Il Sung was a member of the Northeast Anti-Japanese Democratic Coalition Army and was a subordinate of Yang Jingyu. When the Northeast Anti-Japanese Coalition retreated to the Soviet Union and was reorganized into the Soviet Far East International 88th Brigade, the brigade commander was General Zhou Baozhong, later deputy commander of the Northeast Democratic Coalition Army, and Kim Il Sung was one of his battalion commanders.
After the liberation war began, Kim Il-sung said that he would regard China's revolutionary cause as his own revolution. North Korea's largest weapons assistance to the Northeast Field Army was the acquisition of 100,000 weapons by the Northeast Bureau after sending Chen Yun and Xiao Jinguang to north Korean weapons assistance. When the Japanese colonized Korea, heavy industry was basically in North Korea, and Korea collected a large number of weapons and ammunition left by the Japanese throughout the country and gave them to the Northeast Field Army. During the Three Years Liberation War, the number of weapons aided by North Korea was difficult to determine accurately, but the number of weapons aided by a large number alone was as high as more than 2,000 trainwalls.
At the beginning of the Liberation War, the Kuomintang army caused great pressure on the Northeast Field Army with advanced American equipment, and Korea became a large rear area. In 1946, the Kuomintang army launched a large-scale attack on Tonghua, Dandong and other cities, and the logistics organs in these areas, as well as the wounded, retreated to Korea, and many Korean people helped transport supplies. In addition, the logistics department of the Northeast Field Army also used the ports of the DPRK to transport a large number of specialties from the Northeast to Hong Kong for sale, and replaced the medicines and electronic products continued by the Northeast Field Army.
In addition, many Koreans joined the Northeast Field Army as volunteers, and these Koreans, as well as the Korean Volunteer Army, which was originally in the northeast, were reorganized into three Korean divisions and returned to North Korea in 1949. Many people say that these three Korean divisions are all Chinese Koreans, but in fact, it is not, the concept of Korean nationality did not exist until after the founding of New China, and koreans were also Koreans who immigrated from Korea in the last years of the Qing Dynasty, which did not have a very clear boundary at that time.
In 1949, when the overall situation of the Liberation War had been decided, three Korean divisions of the 164th Division, the 156th Division, and the 166th Division of The Four Fields returned to Korea and were incorporated into the Korean People's Army. These three divisions were highly experienced in combat, well-armed, and well-trained, and made great achievements in the subsequent Korean War.