The East Asian crisis was a catalyst for changing Japan's regional position and leadership role and therefore had significant implications for Japan's geo-political and economic relationship with East Asia. The Japanese government maintained the ‘developmental state’ approach in collaborating with the economic restructuring programmes in major East Asian countries after the crisis. Japanese responses to the crisis had significant implications for East Asian regional integration. They clearly indicated the shift in Japan's behaviour and the emergence of a regional leadership role in promoting regional integration in East Asia. This suggests that Japanese confidence in the validity of the developmental state concept prompted the government to reconsider its pro-active role in the establishment of an ASEAN +3 Summit.