Preview: Many in Japan view the U.S.-centered alliance network as the bedrock institution of the regional security structure in East Asia and believe that the U.S.-Japan alliance is the central piece of this network. This essay examines this conception of the regional order and is organized into three sections. The first section provides an overview of the regional security environment, while the next section explains the importance of the U.S.-Japan alliance in the regional security system. The essay then concludes by discussing the prospects for multilateral cooperation to strengthen the regional order.