疾病与唐蕃战争

Disease and the Tang-Tibetan War

在唐朝与吐蕃的战争中 ,青藏高原特殊的地理气候对双方都产生了重大影响 ,高山 (原 )反应是唐军在具有战略意义的大非川战役和青海战役中败北的主要原因之一 ,也是唐军始终无法对吐蕃腹地形成威胁的重要因素。青藏高原上的海拔高程分界线———赤岭也由此成为唐蕃双方实际控制范围的分界线 ,唐人在近百年时间里只能据守海拔相对较低的赤岭以东的河湟谷地。吐蕃人虽然天生适应高海拔 ,却受制于高原人特有的畏热体质 ,在对唐朝展开进攻时往往刻意选择凉爽季节 ,这就限制了其作战周期和战略主动性。疾病始终是影响唐蕃战争格局的不可忽视的重要因素。

The climate and geographic conditions of the Qinghai-Tibet Plateau played an important role in the Tang-Tibetan War.In fact,altitude sickness was one of the major factors causing the defeat of the Tang army in important battles such as Dafeichuan and Lake Qinghai.It was also an important factor preventing the Tang army from entering the heartland of Tibet.The Chiling Mountains,the line separating the higher and the lower regions of the Qinghai-Tibet Plateau,became the borderline of regions respectively under the actual control of the Tang and the Tibetans.For almost a century the Tang army was stopped at Hehuang to the east of the Chiling Mountains,which belong to the lower region of the plateau.Similarly,the Tibetans who were used to high altitudes had difficulty in adapting to hot weather,which also represented a constraint on their timing and strategy in their battles against the Tang army: they had to wait for cooler seasons to launch their attacks.Disease always played a role that should never be overlooked in the Tang-Tibetan war.