Competing Claims in the South China Sea
Potential Paths Forward and Implications for the United States

February 24, 2014

As part of a strategic initiative aimed at deepening understanding in Congress about U.S. interests in Southeast Asia, a group of senior policy experts addressed the nature of overlapping claims in the South China Sea and the implications for U.S. policy in the region


February 19, 2014

The South China Sea is marked by an array of territorial and maritime disputes, and the interests of the United States are deeply entwined in this complex web. The principal countries in these disputes include China, Vietnam, the Philippines, Malaysia, and Brunei, though China’s territorial and maritime resource claims are the most expansive. Specifically, China’s claim to territory within the “nine-dash line” has put the country at odds with many of its neighbors, including U.S. treaty ally the Philippines. [1]

The South China Sea is one of the most important waterways in the world and helps facilitate economic activity throughout Asia. Trade passing through the sea exceeds $5 trillion per year, with U.S. trade making up more than 20% of this economic activity. [2] It is also rich in fisheries and thought to hold vast beds of energy resources. A disruption of freedom of navigation would significantly affect international economic activity, as well as harm global norms that encourage peaceful resolution of conflicts.

On November 22, 2013, the National Bureau of Asian Research (NBR) and the Henry M. Jackson Foundation convened a group of senior policy experts for a roundtable discussion to examine the nature of these overlapping claims in the South China Sea and discuss the implications for U.S. policy in the region. This discussion was part of a strategic initiative aimed at deepening understanding in Congress about U.S. interests in Southeast Asia.

Participants discussed the importance of gathering additional data to determine the nature of features in the South China Sea and thus resolve some of the uncertainty surrounding overlapping territorial and maritime claims. They also explored the implications of the U.S. decision to not yet ratify the United Nations Convention on the Law of the Sea (UNCLOS) on options to assist in pressing for peaceful outcomes of disputes. In the context of the U.S. rebalance to Asia, the United States should work to mitigate the potential for conflict in the South China Sea by building support for the rule of law and promoting the peaceful resolution of overlapping claims.

Disputed Claims

Approximately one hundred territorial features are presently disputed in the South China Sea, [3] and because issues of sovereignty affect which countries are entitled to exploit the potentially lucrative resources around a feature, much is at stake. UNCLOS, to which all claimants are party, provides an international legal framework for determining the ownership of territorial waters and exclusive economic zones (EEZ) based on coastlines and other features. There are five kinds of features: islands, low-tide elevations, rocks, submerged features, and artificial islands or structures. These features are defined by their status at high and low tides, as well as by their ability to sustain human habitation or economic activity. Some categories yield different territorial entitlements, such as territorial seas, contiguous zones, EEZs, and continental shelves. Although it outlines the rules for determining sovereignty, UNCLOS does not provide standards for resolving sovereignty claims.

A key difficulty in navigating the web of claims in the South China Sea is inadequate information. Current data on whether features are above or below water at different tide levels is either unavailable or incomplete. China and other claimants frequently issue maps demarcating their claims, which they then use as evidence to reinforce their respective assertions of sovereignty over features. Some participants in the roundtable discussion argued that a better understanding of the types of features under dispute could better define, and possibly pare down, the overlapping claims in the region. Because the available data is too old or unclear to be useful, participants highlighted this as an area in which the United States could lead to help resolve the conflict.

The Philippines’ Case against Chinese Claims

Recent flare-ups in the South China Sea partly stem from an April 2012 incident between China and the Philippines. On April 8, a Philippines surveillance vessel spotted and moved to arrest Chinese fishermen in disputed waters in the South China Sea. A nearby Chinese coast guard vessel immediately moved in and challenged the Philippines vessel, resulting in a standoff. A rapid escalation soon occurred as the Chinese used nonmilitary vessels to create a physical barrier across the mouth of the reef. In the ten weeks that followed, China used its economic leverage over Cambodia to divide the Association of Southeast Asian Nations (ASEAN) on the dispute and created disunity among member states. [4]

In 2013 the Philippines brought forward an arbitration case to the International Tribunal for the Law of the Sea (ITLOS) to challenge some of China’s claims in the South China Sea. However, roundtable participants expressed concerns that the forthcoming ruling, expected in late 2014 or early 2015, will not do much to resolve the conflict. Although the international law utilized in this case establishes rules for ascertaining what country owns a given area, they are based on the available information, which is not publicly well-developed.

Further undermining the potential of the ITLOS case to resolve the dispute is that parties to UNCLOS have the option to opt out of compulsory resolution of disputes involving questions of sovereignty, which China has done. [5] As such, the suit is proceeding without China, calling into question the eventual effectiveness of the tribunal’s ruling. However, the decision of the Philippines to take this case to arbitration represents an attempt to return to the peaceful resolution of disputes in accordance with international law. As participants noted, the ruling of the tribunal will at the very least draw attention to Chinese actions and force discussion on how to move forward in resolving such disputes.

Discussants highlighted an opportunity for the United States to build a coalition in support of accepting the tribunal’s ruling. They also noted, however, that one potential limitation to the United States’ ability to succeed in this endeavor is that it is not a party to UNCLOS. While Washington generally recognizes the convention as international law, it has not acceded to the agreement due to a lack of support within Congress. It thus may be difficult for the United States to convincingly promote the decisions of the court in this case and any that follows.

Role for the United States and Possible Ways Forward

While the United States maintains a position of neutrality in South China Sea disputes, there is a potential role for it to play in defusing tensions and preventing the escalation of conflict. Assistant secretary of state for East Asian and Pacific affairs Daniel Russel’s February 2014 testimony before Congress cited “growing concerns that [China’s] pattern of behavior in the South China Sea reflects incremental effort by China to assert control over the area contained in the so-called ‘nine-dash line.'” He noted that any use of the line by China “to claim maritime rights not based on claimed land features would be inconsistent with international law.” [6]

The expansion of the U.S. military presence in the region has been noted as a potentially useful tool to help emphasize restraint. Some participants in the roundtable argued that it is in Washington’s interest for Beijing to perceive a real possibility of negative consequences from any irresponsible actions. A lack of perceived cost could lead to more coercion by China, increased instability in the South China Sea, and heightened probability of intensified conflict among claimants in the future. Additionally, to counter this threat, the United States could promote the development of partnerships between regional powers, build partner capacity, and broaden the types of military capabilities it is willing to transfer to other countries. These options would enable those directly involved in the disputes to encourage Chinese restraint and responsible management of overlapping claims.

The prospect of renewed consultations on a Code of Conduct, led by ASEAN, has also been explored as a possible solution to disputes in the South China Sea. [7] While recent progress toward achieving a Code of Conduct has been positive, some participants argued that the United States could not solely rely on this venture to resolve the many competing claims in the South China Sea.

The South China Sea and the Rebalance Toward Asia

Tensions over overlapping claims in the South China Sea take place as the United States is focusing increased strategic, economic, and diplomatic attention on the Asia-Pacific. Participants discussed how the United States could achieve the goals of the rebalance toward the region within the broader context of declining U.S. defense spending. [8] Influence in Asia is not necessarily directly correlated to the amount of money spent. Many elements of the rebalance, such as U.S. participation in regional summits, do not require an exorbitant budget but rather investments of time and diplomacy.

With respect to the South China Sea, the United States should work to promote the harmonization of bilateral and multilateral military partnerships, such as that between the U.S. and the Philippines, to encourage a more cost-efficient allocation of resources. If the region is marked by weak institutions, allies, and partners, U.S. power alone will not deter China from pursuing its territorial goals and interests. The United States should further promote within Southeast Asia its core principles of respect for international law, human rights, and democracy.

U.S. interests in the Asia-Pacific will continue to develop in the coming years. By actively working toward a peaceful resolution of the complex territorial and maritime disputes in the South China Sea, the United States can increase economic prosperity, help ensure stability in the region, and promote the rule of law and freedom of navigation.


[1] The so-called “nine-dash line” is used by China to delineate and assert sovereignty over its maritime and territorial claims in the South China Sea.

[2] Bonnie S. Glaser, “Armed Clash in the South China Sea,” Council on Foreign Relations, Contingency Planning Memorandum, no. 14, April 2012,

[3] John Baker, “Cooperative Monitoring and the South China Sea Disputes,” Banyan Analytics, October 16, 2013,

[4] Ian Storey, “ASEAN and the South China Sea: Deepening Divisions,” interview by Ann Jung, National Bureau of Asian Research (NBR), July 16, 2012, /research/activity.aspx?id=262.

[5] Peter A. Dutton, testimony before the U.S.-China Economic and Security Review Committee Hearing on China’s maritime disputes in the East and South China Seas, April 4, 2013,

[6] Daniel Russel, testimony before the House Committee on Foreign Affairs, Subcommittee on Asia and the Pacific, February 5, 2014,

[7] Carlyle A. Thayer, “New Commitment to a Code of Conduct in the South China Sea?” NBR, October 9, 2013, /research/activity.aspx?id=360.

[8] U.S. Department of Defense, “Defense Budget Priorities and Choices—Fiscal Year 2014,” April 2013,

This report was prepared by Laura Schwartz, an Intern at The National Bureau of Asian Research.