A year and a half since China began rapidly building and militarizing artificial islands in the contested, resource-rich waters of the South China Sea , the states most threatened by Chinese expansion are looking for ways to push back more forcefully. But a series of summits in Southeast Asia this week will illustrate two key dynamics still playing to China's favor: the region's reliance on Chinese investment and the divides inherent to Southeast Asia that will continue to prevent alliances from unifying against China. In Manila on Nov. 17-18, at the annual Asia-Pacific Economic Cooperation (APEC) forum, Beijing will promote its vision of a China-led order in which trade on its terms underpins stability and security in the Western Pacific.