China is the leading naval power in Southeast Asia almost by default. With the effective end of the Russian and U.S. naval presence in the region, it has the geographic advantageous position, and the size and strength of fleet to dominate the region. Japan is still limited psychologically from projecting force into the region and its force structure is inadequate for the task. Taiwan is hopelessly outclassed without the help of other naval powers to distract the full force of the Chinese People's Liberation Army's Navy. The ASEAN to survive the Chinese future must finish its plans to form a defense community, and successfully set aside its own internal differences.
The most glaring absence in Southeast Asia is maritime air power. The navies of the region lack long range SAMs, or air cover, so a fleet of attack helicopters armed with stand-off missiles could dominate the region. Even with the addition of those assets, attack jets can seriously complicate any attempt at Chinese dominance. If only the ASEAN could afford enough of them. Still, aircraft are the cheapest ASM platforms, and the clearest measure of ASEAN willingness to defend themselves will be the acquisition of these craft. By the same token, the measure of the Chinese willingness to dominate the region will be the building of aircraft carriers to give their fleet long range air support, or the building of airfields in those parts of the Paracels and Spratlys that the Chinese own or claim.
The Southeast Asian region is the core of the coming Pacific Century. The nations there are the emerging economies of the 21st Century. Absent a coherent defense policy among themselves and the other maritime policies they may well find themselves back in at the beginning of the 15th Century, once again facing Chinese demands to acknowledge the supremacy of the Chinese ruler.