The authors report the national and international responses to the disaster produced by the Tokyo subway sarin attack. From a worldwide historical perspective, there had never been such a large-scale disaster caused by nerve gas during peacetime. Therefore, this event should be studied from various viewpoints in cooperation with members of the international community. To this end, the Japanese government should help coordinate a large-scale and detailed investigation of the Tokyo subway sarin attack, including the long-term effects of sarin. The authors also recommend that the Japanese Self Defense Forces should be used more effectively in large-scale disasters. The system of direct control of disaster management by the Japanese government could be useful in a large-scale disaster.