During the first century of the Han Dynasty (206 B.C.E.-220 C.E.), an imperial prince, Liu An (d. 122 B.C.E.), gathered together a group of scholars at his court in Huainan, in modern-day Anhui Province. He oversaw a large literary enterprise that produced numerous writings, one of which survives intact: the Huainanzi or Master of Huainan. This work is an encyclopedic survey of all the traditions of knowledge and inquiry known to Chinese society at the time. It also offered itself as a comprehensive ideology of rule for the young Han imperium, claiming to synthesize all that an emperor needed to know to reign over the world. In 139 Liu An presented this great summa to his cousin, the Han Emperor Wu (r. 156-87 B.C.E.). Among the many topics the Huainanzi covers is military affairs; in its fifteenth chapter, "An Overview of the Military." This text is rooted in the great tradition of military writings dating back to the Warring States Period (481-221 B.C.E.) and the acknowledged masterpiece of the genre, the Sunzi bingfa (often translated as "Master Sun's Art of War"). In many striking ways, however, "An Overview of the Military" departs from and contrasts with the Sunzi and other earlier military writings. The Sunzi had been written in an era when warfare was changing rapidly and when theorizing about military affairs was still a controversial endeavor. "An Overview of the Military" was written in an empire built upon the foundation of a routinized, professionalized military, and one in which the teachings of earlier military texts had become conventional wisdom. It thus gives us a window into the ways that the ideas of the military texts were incorporated into the political life of the Chinese empire as its political institutions stabilized and normalized. Liu An and his guest scholars, moreover, brought a novel and distinctive perspective to the problems of military affairs. They did not agree with the Sunzi, for example, that the military was "the great affair of the state." They divided the task of rule into "root" (more essential) and "branch" (more peripheral) components, and marked military affairs firmly as a "branch" rather than a "root" concern. They held that the military had only arisen in latter days in response to the breakdown of the original and organic harmony of human society. This had profound implications for current times: the military could only be correctly used in the restoration of peace. This view of military affairs was deeply influenced by the measurably "Daoist" tendencies of Liu An and his guest scholars. If the Sunzi argues that the commander must win through deception and surprise, "An Overview of the Military" counters that such a feat will be impossible if the commander relies on the faculties of the ordinary human intellect. It thus advocates a unique program of self-cultivation for both the ruler and the commander, one centered on meditative and yogic techniques aimed at breaking through the impediments of ordinary consciousness and producing a state of "spirit illumination." Only in this way, it argues, can the commander penetrate through the confusing and deceptive shifts and changes of military power, developing an insight that can manipulate military force so subtly as to make actual conflict unnecessary. Most remarkably, from our perspective, Liu An and his guest scholars used "An Overview of the Military" to produce a robust argument against the militarized centralization of the Han realm. As a regional prince, Liu An demanded that the sacrosanct sovereignty of local sovereigns such as himself be respected. The military could not be used to uproot regional courts and convert vassal territories to bureaucratized "prefectures and districts." In this way "An Overview of the Military" represents an early Chinese ideal of federalism, one that presciently anticipates the questions underlying the status of territories such as Taiwan, Tibet, and East Turkestan today. In The Dao of the Military: Liu An's Art of War I present my complete translation of the text of "An Overview of the Military." In addition, I provide an extended commentary and analysis of the text and its earlier sources. I hope that this volume will be engaging and illuminating for anyone interested in Chinese military literature or in Chinese history more generally.