The U.S.-Japan alliance continues to be the cornerstone of the U.S.-led security structure in East Asia. Within the parameters of this alliance, the unresolved status of Taiwan still presents one of the most precarious security situations in the region, one that could lead to a major war with China. Within the larger scope of U.S.-China-Japan-Taiwan relations, Japan and Taiwan's relationship would generally be considered the least prominent of all possible combinations. Despite this reality, when pulling back the veneer from this seemingly tertiary regional relationship, there is a depth of interaction that is difficult to categorize and that has the potential to greatly influence security and stability in the region. This book examines Japan and Taiwan's special relationship through the lens of Japan's national interests and assesses the implications for the future of the U.S.-Japan alliance.