One challenge faced historically by the agricultural and stationary Han civilization was that it was surrounded to the north and west by nomadic tribes, with fluctuating borders and populations in the mountains and dense forests to the south. To secure the Han core, China historically fought, and occasionally was overcome by, its neighbors (particularly the powerful nomadic tribes to the north). To manage its regional position, China established a Middle Kingdom policy whereby it kept neighbors at bay with a parallel policy of integration and accommodation for the nearby buffer regions while employing a nominal tributary system to deal with its slightly more distant neighbors. When applied effectively, this required minimal expenditure of wealth or military force to retain a relatively safe central position. But it also offered only minimal real influence or control over the neighbors.
As throughout its history, China’s boundaries underwent constant fluctuations. But it is the Maoist period that largely shaped China’s contemporary boundaries and geopolitical landscape. The internal weakening of the Qing Dynasty in the 18th and 19th centuries provided ample opportunities for imperial exploitation of China by Europe and later Japan. With the Japanese defeat in 1945, China found itself embroiled in a civil war that pitted the Nationalists against the Communists. Manchuria returned to Chinese hands, but Outer Mongolia was under Soviet Control, and Soviet influence was spreading to Inner Mongolia and Xinjiang. Even as Mao fought the Nationalists, he was also preparing to retake the northern buffer regions; he was as concerned about Soviet encroachment from the north and west as he was about the past encroachment of Europeans from the coast.
Mao began to consolidate Chinese communist control over Manchuria and Inner Mongolia, edging the Soviets out. Xinjiang meanwhile had been under the control of successive regional warlords, from Yang Zengxin to Sheng Shicai. Shortly after the end of the civil war, Mao moved to eliminate or coops local warlords and take over Xinjiang. Finally, in 1950 Mao moved against Tibet, which he secured in 1951. The rapid-fire consolidation of the buffer regions gave Mao what all Chinese emperors sought, namely, a China secure from invasion.
China’s response to the outbreak of the Korean War in 1950 reinforced the significance of the buffer regions to Beijing’s security, and served as a reminder of the historic position of Korea as a potential staging point for foreign incursions into China. China’s periphery was tested in the 1950s as the United States covertly backed uprisings in Tibet, in the late 1960s in border skirmishes with the Soviets along the Ussuri River, and in the late 1970s with Vietnam’s westward expansion and China’s counter.
Modern China has formally integrated the buffer regions, stretching from Manchuria in the northeast through Inner Mongolia, Xinjiang and Tibet, and into Yunnan and along the mountains in the south. These territories provide strategic depth but bring their own challenges in the form of internal ethnic relations and cohesion — something perhaps less significant in the past when these lands existed in the fuzzy space between domestic and foreign policy. Ethnic, nationalist and sectarian conflicts and insurgencies continue in Xinjiang and to a lesser extent in Tibet, and localized smaller conflicts occasionally arise in other ethnic buffer regions.
One of Beijing’s greatest fears about the buffer regions stems from the manner in which China assimilated them into the country. Unlike the Soviets, who moved non-Russian ethnic groups around to avoid contiguous ethnicities across borders, China moved Han Chinese into the buffer regions, slowly diluting the local populations. China still fears Pan-Turkic movements spreading through Central Asia into Xinjiang; large, organized ethnic Tibetan populations in India; Inner Mongolian herdsmen potentially seeking reunification with Mongolia; ethnic Koreans on the Chinese side of the Yalu River forging ties with a future unified Korea; and numerous ethnic minority and even militant groups moving along the borders of Southeast Asia.