“Change was the only constant in Japanese prisoner management” (p. 48), argues historian Sarah Kovner in her second monograph, Prisoners of the Empire. Kovner's book is a welcome addition to the growing literature on war and detention in the fields of Asian and US history. Standing on impressive transnational research in government and nongovernmental archives, Kovner complicates the popular consensus that Japan's treatment of Allied prisoners of war (POWs) during World War II was singularly cruel and a systematic effort. By meticulously tracing the steps and missteps of Japan's management of POW camps across its vast wartime empire, Kovner adjudicates from official records that there is no evidence of any top-down directive or an inherent quality of Japanese culture that explains why prisoners suffered. Instead, Kovner cogently argues that maltreatment resulted from the absence of planning and indifference among senior Japanese officials.

Chapter 1 tells a history of international humanitarianism that looks from Japan to the world. As Japan sought recognition from Euro-American powers as a modern, imperial peer, many Japanese statesmen like Sano Tsunetami placed high stakes in humanely treating enemy captives. From here, this chapter accounts for the change in Japan's treatment of POWs over time with the reinvention of bushidō and total war mobilization.

The following chapters on the wartime management of POW camps begin at the outer nodes of the POW camp network—Changi camp in Singapore (chapter 2) and Camp McDonnell in the Philippines (chapter 3). Employing a comparative method across camps, camp command structures, and categories of interned persons, Kovner's account of captivity in Japanese hands lays bare the horrific experiences in many of the camps and transport routes between camps, but it importantly explains why prisoners suffered (and why others did not suffer as much). Essentially, prisoners in Singapore and the Philippines were at the mercy of local Japanese commanders and guards who faced logistical and manpower shortages and prioritized other exigencies. But for Indian, Chinese, and Filipino prisoners, their captivity experience also depended on one's position within the racial hierarchy of Japan's pan-Asianism. In chapter 3, Kovner presents another sobering fact about the infamous “hell ships”: “[far] and away the greatest danger to POWs came from friendly fire” (p. 91), as in the case of a US submarine's sinking of the Arisan Maru that became the “largest loss of American POWs in the entire war.” In chapter 4, Kovner turns to the wartime debates among Allied officials, Japanese officials, and Swiss diplomats and International Committee of the Red Cross delegates.

Chapters 5 and 6 move closer into the territorial core of Japan's empire: Korea and Japan. This spatial structure of the chapters works effectively to make clear Kovner's overarching argument that “when senior Japanese military leaders concerned themselves with Allied POWs, they wanted them to be decently housed, not overworked, and given provisions equivalent to those provided to Japan's own soldiers” (p. 136), as was the case in the “model” camps at Jinsen (Inch’ŏn) and Keijō (Seoul) in Korea. Chapter 6 arrives at camps on the Japanese home front to interrogate “why accounts of the POW experience in Fukuoka are so sharply divergent” (p. 137). Attending to both violence (i.e., executions of captured American airmen) carried out under Japanese officers and POW deaths caused by US firebombing of cities, Kovner shows that the “cruelty and chaos in Japan's POW camps reflected what was going on all across the country” (p. 156). Yet, after Japan's defeat in August 1945, Kovner contends that the ending was only a beginning, and the final three chapters (7–9) address the gargantuan efforts to locating and evacuating POWs, Allied prosecution of war crimes, and the renegotiation of the Geneva Convention on POWs in 1949.

Overall, Prisoners of the Empire offers a corrective to military history, as it sets out to do in the introduction (pp. 8–9). By shifting the history of war from the battlefield to sites of detention, Kovner makes important contributions to understanding empires and total war, as well as masculinity and wartime captivity. In some instances, however, opportunities to be in substantive dialogue with scholarly discussions on POWs and empire and state building in conflicts beyond World War II are left unexplored. For example, the POW issue in the Korean War several years later gave rise to remarkably similar claims by Euro-American powers about the inherent cruelty of the Asian enemy, claims that continue to reverberate in popular memory and history. This small quibble aside, Prisoners of the Empire will be invaluable to scholars of international humanitarianism, Japanese empire, and the Asia-Pacific War, as well as scholars concerned with regimes of detention and modern wars of both the past and present.