Sok Chenda has noted the existence of both institutional and capacity constraints in Cambodia. but these are equally applicable to many other GMs countries. Capacity constraints include the limited authority of local government, lack of strategy, lack of ability to implement key facilities, as well as inward-looking orientation, short time horizons, and overlapping demands (Sok Chenda 2009). Unless national capacities are improved, countries will not be able to implement complementary policies and investments, and thereby take full advantage of the new opportunities provided by regional cooperation. Decentralization may also lead to new identities, or the resurrection of older ones, and to conflicts between the political centre and other regions of the country Burnell 2006) CONCLUSIONS over the past twenty years urban areas in mainland Southeast Asia have been subjected successive rounds of change. First came change as to a result of the adoption of the market economy. Second came regional cooperation, and later economic corridors that explicitly combine economic liberalization, cooperation, and notions of economic space. The fourth wave is increasing economic cooperation with the PRC through economic and transport corridors, CAFTA, and more general economic interaction between the two areas the urban Regional economic cooperation has had an impact on landscape of Southeast Asia since at least as early as colonial times. Trade- ration, rather than the trade liberalization facilitation-focused regional coope urban landscape type exemplified by ASEAN and CEPT is shaping the and reducing in mainland Southeast Asia by lowering transaction costs which risk and uncertainty. Growth triangles and economic corridors, were introduced in the early and latter part of the nineties respectively, will, through their tight relationship between trade and investment on one side, and geography and location on the shape urban landscapes. other, The full impacts of these forces will be felt after 2015 when the GMs is fully connected by corridors and CAFTA provisions apply to all ASEAN countries, including the four mainland Southeast Asian countries that are currently exempt. a de facto decentralization The urban landscape will change, leading to equally. Urban of urban activities, although urban centres will not gain and the "two Rai subcorridor centres located in the Jinghong - chiang Rai subcorridor