杜甫《前出塞》是为哥舒翰征吐蕃事而发吗单芳唐代的外患在北面和西面，唐初尤以北面突厥的威胁为甚。经过多年的努力，突厥逐渐衰落，吐蕃继起，它逐渐扩张，并吞了附近的各个国家，甚至灭了吐谷浑．占有其全部区域，并夺取了唐王朝在西域的四镇大部分土地。到了武后时代... Du Fu “before the plug” is Ge Shu Han expedition Fanfa? Single Fang Tang foreign invasion in the north and west, especially in the early Tang Dynasty Turkic threat is even worse. After years of hard work, the Turks gradually declined. Following the Tubo rule, it gradually expanded and annexed various countries in the neighborhood and even destroyed Tuyuhun. Occupying all of its territory and seizing most of the land in the four towns of the Tang Dynasty in the Western Regions. To post-wu era ...