It is a well known fact that Japan spends only a small percentage of her gross national product on defense. What is not well known, however, is the fact that Japan's defense budget ranks among the top in the world and that her self-defense forces are considered to be amongst the best conventional armed forces in the world. Since empirical studies concerning Japan's military expansion are rare both in Japanese and English, the book takes up this neglected area. It examines Japan's military expansion and the decision-making of her defense policy between 1976 and 2007, focusing on the National Defense Program outline and the guidelines for United States-Japan Defense Cooperation. This book deals with how the bureaucratic politics model applies to the case of Japan's defense policy and demonstrates some similarities and differences between Japanese and United States decision-making.