Joint Development in the South China Sea

By Huy Duong

With the South China Sea disputes remaining intractable, the need to manage them is paramount. Worldwide, joint development of disputed areas has proved to be a hallmark for managing disputes, yet this continues to elude the claimants to the Paracels, Spratlys, Scarborough Reef, and the central part of the South China Sea.

Successful dispute resolutions and joint developments

Dispute resolutions and joint development are not new to the South China Sea countries. These countries have successfully demarcated a number of maritime boundaries, including Indonesia-Malaysia, Malaysia-Thailand, Thailand-Vietnam, China-Vietnam, Indonesia-Vietnam, and Brunei-Malaysia. In the Gulf of Thailand, Cambodia and Vietnam have agreed to an area of “joint historic waters” since 1982. Around the entrance to this gulf, Malaysia, Thailand, and Vietnam have agreements on three areas of bilateral and trilateral joint development, the first of which dates to 1979.

Joint Development

Boundaries and joint development areas in southern South China Sea. Source: Huy Duong, all rights reserved.

These successes depend on the conflicting claims being clear and reasonable—which results in small well-defined overlaps—on negotiations in good faith, and on the absence of sovereignty disputes over islands.

Lessons for the current conflicts

Why have these successes not been repeated for the disputes in the central part of the South China Sea?

First, these disputes involve unresolved sovereignty disputes over islands, which add complexity to the maritime disputes and often carry political and emotional undercurrents. However, this should not matter for the provisional arrangements of joint development because their raison d’être is the existence of unresolved disputes; arrangements for joint development normally define the limits of the disputed areas and a means to share the resources in a way that is independent of the relative strengths of the claims.

Most importantly, there is no agreement on where the limits of the disputed areas are. Joint development of the disputed areas is not possible if there is no agreement on their limits.

China’s actions at various points along the U-shaped line suggest that it is setting the stage for claiming certain rights within the area approximately indicated by that line. This area extends beyond the equidistance line between the disputed islands and other territories, therefore China’s position is inconsistent with international law because according to jurisprudence on maritime delimitation, the waters belonging to these islands would fall far short of this line. China’s position creates a large, asymmetric, ill-defined area of overlapping claims that would make joint development in this area disadvantageous to the other claimants.

Vietnam and the Philippines see the 200 nautical mile exclusive economic zone (EEZ) extending from their undisputed territories as sacrosanct and unaffected by the potential EEZ entitlement of the disputed islands, but neither has stated whether it claims EEZs for these islands elsewhere. Malaysia has been silent on the question of potential EEZ entitlement of the disputed islands. Brunei only claims Louisa Reef, and is unlikely to demand EEZs for other features.

Comparing this situation with successful dispute resolutions and joint developments elsewhere suggests that these successes have not been repeated here because the following factors are missing: clear and reasonable claims by all parties, an agreement on where the disputed areas are, and good faith.

A possible definition of the joint development areas

Despite the unknowns, it is clear that China seeks to maximize the disputed areas, while the Philippines, Malaysia and Brunei are likely to seek to minimize them. Vietnam seeks to reduce the disputed areas, but its need to reduce them to the 12 nautical mile territorial sea around the disputed islands is probably less acute than that of the Philippines and Malaysia. This is because most of the disputed islands do not lie deep in the 200 nautical mile EEZ emanating from Vietnam’s undisputed territories. Nevertheless, it would be beneficial for Vietnam, the Philippines, Malaysia, and Brunei to take a common position, so their views are likely to converge.

The greatest difference will be that between China’s wish to maximize the disputed areas and the other countries’ wish to reduce and minimize them.


Could the “quarter distance” lines, in black, be the maximum limits for the disputed waters? Source: Huy Duong. All rights reserved.

A compromise might be for the claimants to define the areas of joint development along the lines used by the International Court of Justice in its solution to the Nicaragua-Colombia dispute, which gives Colombia’s small offshore islands no EEZ, and larger ones an EEZ that extends a quarter of the distance to Nicaragua’s coastal islands. If a similar arrangement is applied to the South China Sea, then the maximum limits of the areas of joint development will be the black lines in Map 2, which seems to be a reasonable compromise for all parties.

The question is whether every claimant has enough good faith to define the areas of joint development in any reasonable manner.

Mr. Huy Duong contributes articles on the South China Sea to several news outlets including the BBC and Vietnam’s online publication VietNamNet. See more by this author.