Despite the consensus that economic diplomacy played a crucial role in ending the Cold War, very little research has been done on the economic diplomacy during the crucial decades of the 1970s and 1980s. This book fills the gap by exploring the complex interweaving of East–West political and economic diplomacies in the pursuit of détente. The focus on German chancellor Willy Brandt’s Ostpolitik reveals how its success was rooted in the usage of energy trade and high tech exchanges with the Soviet Union. His policies and visions are contrasted with those of U.S. President Richard Nixon and the Realpolitik of Henry Kissinger. The ultimate failure to coordinate these rivaling détente policies, and the resulting divide on how to deal with the Soviet Union, left NATO with an energy dilemma between American and European partners—one that has resurfaced in the 21st century with Russia’s politicization of energy trade. This book is essential for anyone interested in exploring the interface of international diplomacy, economic interest, and alliance cohesion.