From 1954 to the present day, this volume takes an in-depth look at the fundamental nature of the relationship. The book addresses the historical origins of security relations in both countries and the ways in which these formed the basis for their postwar security cooperation and examines the negotiated set of shared military, economic and political agreements and expectations which have shaped their relationship. The work's main focus, however, is the way in which this alliance has evolved. Four cases of significant policy change--in 1960, 1981, 1987 and 1997--are analyzed along with a discussion of the relevant strategic and tactical realities of the time. The reactions of the United States and Japan to recent events such as Iraq's Kuwait invasion and the 2001 terrorist attacks on America are also discussed. Numerous tables are included.