The Zunghar nation developed in the early seventeenth century from nomadic tribes of Western Mongols who had established a homeland beyond the Altai Mountains, astride the modern China-Kazakhstan border. By 1700, the Zunghars had created an empire that included the oasis towns of Eastern Turkestan, and were sufficiently strong to pose a threat to both their Russian and Chinese neighbors. Following several conflicts with the nomads, the Chinese emperor, Qianlong, grasped an opportunity to conquer Zungharia in 1755. He easily succeeded but, after Chinese forces withdrew, the Zunghars rose in revolt, prompting the Qing ruler to seek a final solution to his Zunghar problem. Acting at the behest of the emperor, Chinese armies intentionally exterminated at least 180,000 people during the ensuing campaign, representing some 30 percent of the Zunghar population. An outbreak of smallpox ravaged the remainder, leaving less than one-third of...