Farther east, in the main theater of battle against the Tanguts, Sung troops mobilized for a second-wave offensive that would push into the Heng-shan highlands. In retribution for the Sung conquest of Ch’ing-t’ang, Hsi Hsia troops went on a rampage in northwestern Ch’in-feng circuit in the ninth month of 1104, killing tens of thousands of civilians in the two border prefectures ofWei-chou and Chen-jung chün. Alarmed at these atrocities, Ts’ai Ching appointed the general T’ao Chieh-fu as pacification commissioner (chingl ¨ueh an-fu shih) of Fu-yen circuit, entrusting him with defending the eastern stretch of the Sung–Hsi Hsia frontier. Like his former commander Chang Chieh, T’ao formulated an “advance and fortify” strategy to defend the Hengshan highlands from future Tangut incursions and reprisals by establishing a solid defense perimeter. In the spring of 1105, Sung forces captured and fortified the strategic walled city of Yin-chou, later staving off a large-scale Hsi Hsia offensive to recapture the surrounding area. By projecting Sung military power ever closer to the heartland of the Hsi Hsia Empire, T’ao Chieh-fu managed to bring the Tanguts back to the bargaining table. After his troops were defeated in the battle over Yin-chou, Emperor Ch’ung-tsung of the Hsi Hsia sued for peace through a Liao emissary. A cease-fire was proclaimed in the seventh month of 1106, but diplomatic negotiations soon bogged down over the issue of ceding captured territory. In the end, a compromise treaty was reached, in which the Sung retained its hegemony over the Ch’ing-t’ang region, but returned Yin-chou as a concession to the Tanguts. Through the demotion of T’ao Chieh-fu to a prefectural post, the Sung court demonstrated its willingness to abandon its “advance and fortify” strategy for the foreseeable future.
The truce held for seven years, while Hui-tsung’s court remained divided between proponents of aggression and appeasement. Frustrated by his demotion and the cession of hard-won territory to the Tanguts, T’ao Chieh-fu advocated extreme measures. Apparently, he managed to convince several members of the Council of State that the only way to stabilize the border and to prevent further incursions was to decapitate the Hsi Hsia regime with an all-out assault upon its heartland of Hsing-chou and Ling-chou. Chao T’ing-chih, who briefly served as chief councilor in 1107, after Ts’ai Ching’s first departure from court, opposed T’ao’s invasion plan as costly and imprudent. Unswayed by the hawks at court, Hui-tsung was either unwilling or unable to commit troops and resources on another prolonged border campaign. A few years later, external pressures finally tipped the balance, providing the emperor with a legitimate casus belli. Starting in 1109, a series of escalating disagreements over the demarcation of the unfixed Sung–Hsi Hsia frontier brought the rulers of both empires to the brink of war. In 1113, in an attempt to convince the Sung to agree on a redrawn borderline, the Hsi Hsia ruler Ch’ung-tsung resumed the construction of fortifications in the disputed frontier territory. To further destabilize an already precarious situation, the Ch’iang chieftain Li O-to switched allegiance to the Hsi Hsia and began raiding Sung positions in Huan-chou. The Tanguts continued to buttress their position in Hengshan, in 1114 building a strategic fortification at Tsang-ti-ho, on the northern edge of the Sung commandery of Pao-an. After this provocation, bellicose elements at court convinced Hui-tsung to commit tens of millions of strings of cash and hundreds of thousands of soldiers to a renewed offensive in the northwest.
At the onset of hostilities in the fourth and final Sung-Tangut conflict, Hui-tsung appointed T’ung Kuan supreme commander of the imperial forces in all six border circuits. For the next five years, T’ung overcommitted Sung forces to fight in a conflict with unattainable objectives. Just as they had a decade before, Sung troops made simultaneous incursions into Ch’ing-t’ang and Heng-shan. Never achieving the final breakthrough they had expected, the emperor’s generals squandered massive resources and caused the deaths of (according to one estimate) several hundred thousand imperial troops. In 1115, a force of one hundred and fifty thousand soldiers under the command of Liu Fa moved north from Huang-chou to reoccupy the Ch’ing-t’ang region. Pushing deep inside enemy territory, Liu’s army slaughtered a Tangut garrison to conquer the stockade at Ku-ku-lung, on the Tibeto-Tangut border. The same year, the Chin-feng military commissioner Liu Chung-wu and a man identified as Wang Hou led imperial troops from four circuits to besiege the newly constructed Tangut fort at Tsang-ti-ho, where nearly half of them – more than a hundred thousand men, by one estimate – were massacred. According to the Sung shih account, Wang bribed T’ung to conceal these massive casualties in his reports to the emperor. In 1116, Liu Fa and Liu Chung-wu united two circuit armies to penetrate farther into the Hao-tan valley, forcing the surrender of Jen-to-ch’ üan, a Hsi Hsia walled town upstream from Ku-kulung. Undaunted by the carnage of the previous year, a hundred thousand Sung troops conquered the strategic fortress at Tsang-ti-ho, the original bone of contention in this final phase of the Sung-Tangut conflict.
But after these promising initial victories, the tide of battle turned against the Sung, as mounting casualties forced the court to admit defeat. Seeking to even the score, the Tanguts staged a successful surprise attack on the Sung walled town of Ching-hsia during the relatively snowless midwinter of 1116– 17. In the final analysis, what forced the Sung court to abandon the campaign was T’ung Kuan’s strategic incompetence, which impelled him to commit what remained of his armies to an impossible mission. Plotting to eradicate the Tangut menace once and for all, T’ung forced an unwilling Liu Fa to lead an invasion of Shuo-fang, at the core of the Hsi Hsia empire. Leading two hundred thousand troops into what quickly became a suicide mission, Liu was attacked by a massive contingent of Tangut forces outside the walled city of T’ung-an. Walking into a deadly trap with no escape route and short of food and water, Liu’s armies were encircled by three hundred thousand Hsi Hsia infantry and cavalry, commanded by the Hsi Hsia prince Ch’a-ko. A hundred thousand Sung troops survived, fleeing some twenty miles under the cloak of night, only to be pursued and ambushed the next day, when Liu was beheaded. Soon thereafter, Ch’a-ko’s forces besieged the Sung cliffside fortress at Chen-wu, and Liu Chung-wu and his remaining garrison were decimated. As with prior defeats, T’ung Kuan covered up these massacres, preventing the news from reaching Hui-tsung; as late as 1119 he was claiming continued victories in his reports to the throne.
After these bloodbaths, whose casualty count exceeded that of the Yung-lo ch’eng debacle of 1082, T’ung Kuan had no choice but to concede defeat. When T’ung suggested a cease-fire to the Tangut command, the Hsi Hsia extracted an apology from Hui-tsung, who promulgated an edict that abolished the military command structure in the six north-western military circuits. In its final and most brutish phase, the Sung-Tangut war had proven a huge waste of financial resources and human life. Sacrificing hundreds of thousands of soldiers to briefly recapture a barren stretch of land, T’ung Kuan had miscalculated the strength of the Hsi Hsia military. Following the conclusion of the Sung-Tangut peace agreement, Hui-tsung’s court shifted its attentions from the northwest to the north-eastern frontier. In the early 1120s, the empire was shaken by popular uprisings in the southeast, which forced the court to divert military resources to quell domestic unrest. The massacres at T’ung-an and Chen-wu foreshadowed the carnage in years to come, when the emperor and his ministers embroiled the Sung in a near-fatal conflict with the Jurchen. In retrospect, the sacrifice of imperial troops in the Shuo-fang offensive was rendered meaningless by the Chin conquest of 1127, after which the truncated Southern Sung Empire would no longer even adjoin Tangut territory. Judging from their abject failure to subdue an adversary of lesser strength, the Sung armed forces would never stand a chance against the Jurchen, who were swallowing everything in their path, as they stormed to dominance over the territories on both sides of the Great Wall. As with the Tangut conflict, the ignominious Sung defeat in the next series of border wars did not result from any quantitative disadvantage, but from strategic, tactical, and diplomatic ineptitude.
