In less than five months after Junichiro Koizumi was inaugurated as Japanese Prime Minister, the terror attacks happened in U.S., which is the allied nation with Japan and is responsible for the security of Japan. Under the threat of international terrorism and the request of aid from U.S., it's urgent for the Junichiro Koizumi Cabinet to abandon the long-held defense policy and submit new aid policy to promote Japan's position in security affairs. The issue will be discussed in this study.