Solid political relations between China and the Mekong countries are no doubt the most important foundation for regional cooperation. All five GMS countries are members of ASEAN. The process of cooperation with these five will therefore be influenced not only by the relations between China and these countries but also by the relations between China and ASEAN as a whole. The normalization of China’ relations with ASEAN, which commenced in the early 1990s, has produced statements of cooperation and several treaties on trade, investment and technology transfer, thereby laying the overall basis for cooperation and development in the region. In October 2003, China signed the Treaty of Amity and Cooperation with Southeast Asia, which was followed by a joint statement to establish a strategic partnership toward peace and prosperity ( people’s Daily, 8 October 2003). This was a milestone that inaugurated a new era in China-ASEAN relations.