The average load capacity of one Chinese train car is normally 60 tons, with about 20 cars in each cargo train. This would mean each train carrying troops and equipment to Chinese military forces in Tibet could transport 1,200 tons, and thus 11 trains traveling both ways would be enough for each day. In time of war, the actual number of trains running on the railroad could double to roughly 20 trains both ways each day.

Supposing the total weight of the equipment and combat materiel needed for one rapid reaction division of the Chinese army was around 15,000 tons, the Qinghai-Tibet railway could transport a whole rapid reaction division in one average day. In other words, within every one-and-a-half to two days, China could move one rapid reaction division from the Chengdu Military Region or one rapid reaction division from the Lanzhou Military Region to Tibet.

China's air transport capability also needs to be taken into consideration. Additional airborne troops, rapid reaction troops and armed police could be directly delivered to Lhasa from the air. Since air-drop operations would take place in the Tibet region, there would be no need for ground-based air defense firepower. Thus, the No. 15 Airborne Division could be air-dropped to Tibet, and equipment such as airborne fighting vehicles could be put to use.

In recent years China has made great effort to revamp the Qinghai-Tibet highway and the Sichuan-Tibet highway. National highways 214, 317 and 109 -- the shortest routes into Tibet by land -- are now all asphalted. If China were to have a military confrontation with India, highway transport could be more reliable should the Qinghai-Tibet railway be damaged.

The railway would allow the 61st Plateau Rapid Reaction Motorized Division of No. 21 Group Army under the Lanzhou Military Region and the 149th Rapid Reaction Motorized Division of the Chengdu Military Region to quickly enter Tibet.

Because of the presence of U.S. military troops in Afghanistan and the escalating independence activities in the southern part of Xinjiang -- northwest China's primarily Muslim Uyghur ethnic region -- the Xinjiang Military Region and the Lanzhou Military Region are now the key forces to guard against internal riots in that part of the country. This is why the forces of the Chengdu Military Region were the first to be deployed in Tibet.

In addition, the riots in Tibet quickly spread to Gansu province, which borders Xinjiang; therefore the Xinjiang and Lanzhou Military Regions may face the new mission of cracking down on Tibetan independence movements as well as Muslim riots and the traditional Uyghur independence activities.

Once the Uyghur separatist movement in Xinjiang and the independence activities in Gansu and Tibet intensify, the 61st Rapid Reaction Division stationed at Tianshui in Gansu province will be the first one to be called upon in the crackdown. In addition, the No. 12 Armored Division, stationed at Zhangye in Gansu province, also may be mobilized.

The 4th Motorized Infantry Division of Xinjiang Military Region was the first local combat unit to receive new equipment in the region, including the T-92 100mm wheeled assault cannons. Obviously, this division is now transforming into a rapid reaction unit and probably will be used to deal with any riots in southern Xinjiang. Besides, this division is also quite close to the Afghanistan border.

The 6th Motorized Infantry Division, stationed at Kashi, is the only mechanized combat unit in the Xinjiang Military Region. It is also close to Afghanistan and is located right in the heart of southern Xinjiang. Should Uyghur independence activities break out of control, the above two divisions would be the first to be dispatched.

As for the Urumqi, the capital of Xinjiang, it is covered by the 11th Brigade. As is widely known, the 63rd Division of the original No. 21 Group Army and the 7th Division of the Xinjiang Military Region have been restructured into the Armed Police No. 63 and No. 7 Divisions, and are stationed at the cities of Pingliang and Ili, respectively.

(Andrei Chang is editor in chief of Kanwa Defense Review Monthly, registered in Toronto.)