Much to the dismay of India, which has a border dispute with China involving a mountainous area of northeastern India (the state of Arunachal Pradesh) adjacent to Tibet, China has been increasing its military activity in Tibet. This, for India, means that China may not just be making noise about their border dispute. To some Indians, it seems quite logical that China might just suddenly seize the disputed territory (as they did with another disputed area in 1962) and dare India to do anything about it. Both nations have nuclear weapons, and the Chinese might conclude that India would not risk nuclear war over some mountainous, thinly populated, border area. This tactic became more of a possibility as China recently built the first railroad into Tibet, along with many roads leading up to the Indian border, as area where, in peacetime, a lot of roads were not needed.
The immediate source of all this anxiety are a series of Chinese military operations in Tibet. In October, for the first time, China held joint army and air force training exercises there. Two months earlier, China conducted its first combat parachute drop in Tibet. The average altitude on the vast Tibetan plateau is 4000 meters/14,000 feet. This means parachutists have to jump from a higher altitude, because of the thinner air and the longer time it takes for the parachute to open. The reduced air pressure also brings on altitude sickness for the troops, especially after something as strenuous as a parachute jump, and the frantic activity following the landing. The Chinese Army wants to find out how well prepared it is to deal with these problems.
The parachute troops went through altitude acclimatization training beforehand, as the Chinese already knew what happened when you send military units straight to the high plateau. This happened two years ago, when there was an uprising in Tibet. Many of the troops sent in soon fell ill from altitude sickness. The acclimatization training detects those troops who would get ill quickly, and the worst of these are kept closer to sea level. The Chinese also have to deal with the fact that much of their frontier areas are covered with mountains and hills, averaging 3,000 meters (9,300 feet) in height. Training in Tibet gets the paratroopers ready to operate in all these areas.
But many other types of troops are being prepared for duty in Tibet. A few weeks before the parachute drop, Chinese J-11 jet fighters were seen, for the first time, training over Tibet. J-11s are the most modern Chinese made fighters (they are also illegal Chinese copies of the Russian Su-27). While fewer than 150 J-11s have been built since they were introduced in the late 1990s, they are appearing in more unexpected places (like the Chinese naval air force). Until recently, the Chinese Air Force has no combat aircraft stationed in Tibet, although older (MiG-21 clones) J-7s appeared to be flown in regularly, for temporary duty at major commercial airports. But now China is basing combat aircraft permanently in Tibet.
The main reason for not previously stationing fighter squadrons in Tibet probably has to do with the high altitude of the area, and the expense of moving the large quantities of fuel and other supplies needed to maintain air units. There is only one rail line into Tibet (recently built) and few heavy duty truck roads.
China still has a serious problem in Tibet with altitude sickness among its troops. This illness occurs when people who grew up near sea level (most of the world's population) move to altitudes greater than 2,100 meters (7,000 feet). Below that, the air contains 21 percent oxygen. Above that, the weaker air pressure lowers the amount of oxygen the body can absorb. That produces "altitude sickness", manifested by shortness of breath, disorientation, nosebleeds, nausea, dehydration, difficulty sleeping and eating, headaches and, if you stay up there long enough, chronic disability.
The average altitude of Tibet is 4,100 meters (14,000 feet). Most people can adapt, sort of, to the altitude sickness. Some can't. But the Tibetans have evolved to deal with it. The majority of Chinese soldiers coming to the Tibetan highlands (which is most of Tibet) require a few days, or weeks, to acclimate. But they are still susceptible to altitude sickness if they exert themselves, especially for extended periods. This makes Chinese military personnel in Tibet much less effective.
Researchers recently discovered that most Tibetans evolved in the last 3-6,000 years to deal with this problem. It appears that the most of the people moving to, and staying in, highland Tibet, were those with the rare genes that made them resistant to altitude sickness. These people became the dominant population in Tibet, mainly because they were healthier at high altitudes. Nearly all Tibetans have this gene (which controls how their red blood cells operate, to maintain sufficient oxygen levels). Very few lowland Chinese have these genes.
The Chinese military is spending a lot of time, effort and money trying to solve this problem. Currently, most of the troops in the Chinese Chengdu Military Region are in the eastern, lowland half. In the western portion (Tibet), they station the 52nd and 53d Mountain Brigades, and struggle to keep these 5,000 troops fit for duty. If there's an emergency, as there was two years ago, the nearby 13th and 14th Group Armies can send troops from their lowland bases. Over 20 percent of these troops will be hampered by altitude sickness once they reach the highlands, and commanders are trained to deal with that.
Chinese troops operating at the highest altitudes (4,500 meters, on the Indian border) now have access to exercise rooms (one of 1,000 square meters and another of 3,000 square meters) that are supplied with an oxygen enriched atmosphere. Troops exercising in these rooms increase the oxygen in the blood, and are much less likely to get hit with a case of altitude sickness. Thus the troops can stay in shape without getting sick. For border patrols at high altitudes, troops usually carry oxygen bottles and breathing masks.
So far, the Chinese have only been able to limit the attrition from altitude sickness, not eliminate it. Given the alertness required of aircraft maintenance personnel, and pilots preparing for flights, plus the logistical problems, the air force has declared Tibet fit to visit, but not to base a lot of aircraft units in. Still, the Chinese air force may one day have to fight in the air space over Tibet, so some training up there is in order. In any case, the Chinese are hustling to be more ready, with more troops (than India) ready for combat on the world's highest battlefield.