Given the steady output of scholarly studies on the origins of the Cold War over the past seven decades, one might legitimately wonder whether there is room for substantially new contributions on the topic. Between Containment and Rollback demonstrates that the opportunity still exists. For nearly a quarter of a century, Christian Ostermann has been the guiding force behind the Cold War International History Project (CWIHP) under the Woodrow Wilson International Center for Scholars. Untold numbers of scholars, of whom I am one, have benefitted from this program. It is hard to imagine how anyone could conduct serious scholarship on the Cold War without turning to the CWIHP's enormous archives of previously unreleased documents from all sides in the conflict. In this new book, Ostermann has drawn on these holdings himself, as well as the archives of other repositories, such as the U.S. Library of Congress and the U.S. Department of State. He has produced a nuanced account of the efforts of U.S. policymakers to make sense of the developments surrounding the post-1945 occupation of Germany, including the Soviet Union's strategic goals, the daunting challenge of reconstruction, and the emergence of rival German states.One of Ostermann's most important contributions is the insight he provides into the decision-making of key figures involved in the formulation of U.S. policy toward Germany. In particular, his treatment of General Lucius D. Clay, the deputy head of the U.S. occupation government, stands out. Historians have sometimes portrayed Clay as the stereotypical Cold Warrior. By contrast, in Ostermann's account the general comes to life as a puzzle solver and a practically minded administrator who was sensitive to the complex dynamics of the early occupation period. Far from having formed any preconceptions about the intentions of the other occupation powers, Clay was intent on devising a unified strategy that would be responsive to the reasonable demands of his country's allies—importantly, the Soviet Union—while simultaneously attempting to whittle down the interzonal boundaries that hindered Germany's recovery.Ostermann also sheds new light on the organizational context of U.S. policymaking. One notable example is his analysis of the inner workings of the U.S. High Commission's little-known Political and Economic Projects Committee (PEPCO). Composed of a variety of officials from the commission's diverse branches, PEPCO was instituted to coordinate the body's operations. However, it quickly became a significant voice in interpreting Soviet and East German behavior and advocating economic and psychological warfare against the German Democratic Republic (GDR).Finally, Ostermann casts light on the perceptions of U.S. policymakers at crucial times in the making of U.S. policy toward Germany, both before the formation of the rival German states in 1949 and in the years immediately afterward. U.S. officials were ambivalent about doing anything that might accelerate the flight of refugees from the GDR. After the interzonal boundary between East and West Germany was closed, they worried about the economic costs of resettlement and, more importantly, feared that the exodus would destabilize the precarious postwar order. At this early date they also wondered whether East Germany's leaders would take steps to seal off the border between East and West Berlin. Barely a decade later, in August 1961, this actually happened.Ostermann does not concern himself with the familiar grand debates about when the Cold War started and which country or leader bore the greatest responsibility for starting it. He was wise not to delve into this controversy. What emerges from his research is a differentiated perspective on the events leading to the division of the European continent into hard-and-fast strategic and ideological blocs. In his account, U.S. policymakers were constantly struggling to discern the motivations of their occupation partners, devise sensible strategies and counterstrategies, and adapt to ever-changing realities on the ground. At times, they were slow to catch up with the developments around them. For example, they were surprised by the speed with which the foundations for the GDR were consolidated. In both the Truman and the Eisenhower administrations there was room for disagreement about how to proceed, but there was not a lot of high drama. Most of those involved had little enthusiasm for grandiose strategies. In fact, Ostermann demonstrates that much of the drama was reserved for these officials’ interactions with their European counterparts, above all the headstrong West German Chancellor Konrad Adenauer.Between Containment and Rollback suggests that if there was a single factor that united most U.S. policymakers, it was much more “containment” than “rollback.” In fact, even the word “containment” must be qualified insofar as it implies a unified and coherent strategy that in reality was present only intermittently. Nonetheless, no matter how one characterizes U.S. aims, Ostermann succeeds in presenting a persuasively non-deterministic study of a highly consequential moment in modern history.