China's Maritime Disputes

The East and South China Seas are the scene of escalating territorial disputes between China and its neighbors, including Japan, Vietnam, and the Philippines. The tensions, shaped by China's growing assertiveness, have fueled concerns over armed conflict and raised questions about Washington's security commitments in its strategic rebalance toward the Asia-Pacific region.

We are strongly committed to safeguarding the country's sovereignty and security, and defending our territorial integrity.

Chinese President Xi Jinping

Mapping the Claims

Six countries lay overlapping claims to the East and South China Seas, an area that is rich in hydrocarbons and natural gas and through which trillions of dollars of global trade flow. As it seeks to expand its maritime presence, China has been met by growing assertiveness from regional claimants like Japan, Vietnam, and the Philippines. The increasingly frequent standoffs span from the Diaoyu/Senkaku Islands, on China’s eastern flank, to the long stretch of archipelagos in the South China Sea that comprise hundreds of islets. The U.S. pivot to Asia, involving renewed diplomatic activity and military redeployment, could signal Washington’s heightened role in the disputes, which, if not managed wisely, could turn part of Asia’s maritime regions from thriving trade channels into arenas of conflict.

East and South China Sea Claims


China claims the largest share of territory in the South China Seas, basing its assertions on historical grounds demarcated by a nine-dash line it drew in 1947. It does not adhere to the international protocols set out by the United Nations Convention on the Law of the Sea (UNCLOS), and has clashed militarily with Vietnam and the Philippines over the Paracels and Spratly Islands. It has also resisted attempts to resolve the disputes through UNCLOS or regional body ASEAN, preferring to pursue conflict resolution bilaterally. China’s maritime claims extend to the Diaoyu/Senkaku Islands in the East China Sea, where it has clashed with Japan. Rising nationalism in both countries and a long wartime history have escalated tensions despite highly interconnected economies.


Taiwan, where the Koumintang regime settled after defeat by communists on the mainland in 1949, adheres to the same nine-dash-line claim as China in the South and East China Seas. It currently has a presence on the Spratly and Pratas Islands.


The Philippines claims the Paracel and Spratly Islands based on its EEZ and continental shelf zones. Tensions reached an inflection point with the Chinese occupation of the Spratly’s Mischief Reef in 1994, leading to the first instance of combat between China and an ASEAN member other than Vietnam. Much of Manila’s territorial tension with Beijing centers around competition for resource development, and skirmishes have erupted regularly since March 2011. In early 2013 the Philippines was the first claimant country to launch an arbitration case under UNCLOS against China’s South China Sea claims.


Malaysia claims some islets in the southern Spratlys, and has occupied five of them since 2009. In 1991, it developed a resort and built an airstrip on Swallow Reef to promote tourism, prompting fellow claimants, including the Philippines, Vietnam, Brunei, and China, to protest. It clarified its claims in 2009 with the joint Vietnamese-Malaysian submission to UNCLOS on the limits of the continental shelf, and maintains a less confrontational relationship with China than other claimants.


While Brunei has not made any formal claims or engaged in any confrontation with other claimants, it lays claim to the Louisa Reef and Rifleman Bank, two formations in the southern Spratlys, based on its EEZ. Brunei’s territorial claims overlap those of neighboring Malaysia, and juts into those of China, Vietnam, and the Philippines. It does not occupy any of the islands, nor does it have a military presence in the South China Sea.


Japan claims it annexed what it calls the Senkaku Islands in 1895. It retained residual sovereignty over the islands after the Treaty of San Francisco in 1951, and the United States returned full control of the territory to Tokyo after the Okinawa Reversion Treaty in 1971. Japan views the Treaty of San Francisco and this reversion agreement as validation of its sovereignty over the islands.


Vietnam has been one of the most vocal claimants in the South China Sea dispute. It claims the Spratly and Paracel Islands based on its EEZ and continental shelf zones, and joined Malaysia in May 2009 in a joint submission of territorial claims in the South China Sea to UNCLOS. Vietnam fought China in 1947 over the Paracels, which China occupied, and again in 1988 when China’s navy sank three Vietnamese vessels, killing seventy-four Vietnamese sailors on the Johnson Reef in the Spratlys. The confrontation marks China’s first armed conflict over the Spratlys, and one of the most serious military clashes in the South China Sea.

Provocations against Japan’s sovereign sea and land are continuing, but they must not be tolerated.

Japanese prime minister Shinzo Abe

Historical Context

China’s maritime disputes span centuries. The tug-of-war over sovereignty of the Diaoyu/Senkakus in the East China Sea can be traced to the Sino-Japanese War of 1894, while Japan’s defeat in World War II and Cold War geopolitics added complexity to claims over the islands. The fight over overlapping exclusive economic zones in the South China Sea has an equally complex chronology of events steeped in the turmoil of Southeast Asian history. Globalization—including extensive free trade pacts between claimants—and recent developments like the U.S. “pivot” to Asia have further connected the two disputes. As China’s economic ascent facilitates growing military capabilities and assertiveness in both seas, other regional players are also experiencing their own rise in nationalism and military capability, and have exhibited greater willingness to stake territorial claims.

To be realistic about it, how does one push around a superpower?

Philippine President Benigno Aquino

By the Numbers

$5.3 trillion in total trade passes through the South China Sea every year.

Source: The White House

There are 11 billion barrels of oil in South China Sea and 190 trillion cubic feel of natural gas.

Source: U.S. Energy Information Administration

90% of Middle Eastern fossil fuel is projected to go to Asia by 2035.

Source: World Energy Outlook 2012 prepared by the International Energy Agency (IEA)

China's military spending has increased 175% since 2003.

Source: SIPRI Trends in Military Expenditure (PDF), 2012

Japan is donating 10 coast guard boats to the Philippines at cost of $10 million

Source: Philippine Daily Inquirer

More than 90% of China & Japan have unfavorable impressions of each other, the highest in nine years

Source: The Genron NPO

The South China Sea issue is not just about competing claims; it’s about peace and stability in the region.

ASEAN Secretary General Le Luong Minh

Policy Options

Thousands of vessels ply the East and South China Sea waters, from fishing boats to coastal patrols and naval ships. Increasingly frequent clashes between China and its neighbors heighten the risk that miscalculations by sea captains or political leaders could trigger an armed conflict, which the United States could be drawn into through military commitments to allies Japan and the Philippines. Policy experts believe that a crisis management system for the region is crucial.


A range of preventive measures could ease regional tensions and de-escalate the risk of military conflict. Experts including Elizabeth Economy, Sheila Smith, Joshua Kurlantzick, and Simon Tay weigh the options.

Resource Sharing

Claimants in both the South China Sea and East China Sea could cooperate on the development of resources (PDF), including fisheries, petroleum, and gas. A resource-sharing agreement could include bilateral patrolling mechanisms, which would deter potential sources of conflict like illegal fishing and skirmishes arising from oil and gas exploration. More collaborations in the mold of joint fishery deals like those between China and Vietnam and Japan and Taiwan could mitigate risk by sharing economic benefits.

Military-to-Military Communication

Increased dialogue between military forces has the potential to reduce the risk of conflict escalation. Communication mechanisms like military hotlines to manage maritime emergencies, similar to the one set up by China and Japan and the one that China and Vietnam agreed to institute in June 2013, could be established among all claimants. These hotline systems would connect leaders in the event of a crisis that could arise from such mishaps as naval maneuvers misinterpreted by captains of merchant vessels or fishermen. Lastly, joint naval exercises could support greater military transparency and help develop shared rules of the road.

Building a Multilateral Framework

The development of a multilateral, binding code of conduct between China and ASEAN countries is often cited as a way of easing territorial disputes in the South China Sea. The parties have already agreed upon multilateral risk reduction and confidence-building measures in the 2002 Declaration on the Conduct of Parties in the South China Sea, but none have adhered to its provisions or implemented its trust-building proposals. While China has historically preferred to handle all disputes bilaterally, the resumption of negotiations between Beijing and ASEAN still holds promise for reinvigorating a multilateral framework toward greater cooperation and conflict resolution.

International Arbitration

Bringing territorial disputes to an international legal body presents another means of conflict mitigation. The International Court of Justice and the International Tribunal for the Law of the Sea are two forums where claimants can file submissions for settlement. In July 2013, a UN tribunal was convened in The Hague to discuss an arbitration case filed by the Philippine government contesting the legality of China’s territorial claims in the South China Sea. An outside organization or mediator could also to be called upon to resolve the disagreement, although the prospect for success in these cases is slim given China’s likely opposition to such options.


In the event military conflict erupts, policy experts including Elizabeth Economy, Sheila Smith, and Shen Dingli outline a few immediate options facing the countries involved.


Escalatory actions would likely trigger ramped up diplomacy. The United States could initially serve in a mediation role in the event of crisis erupting in either sea. In the South China Sea, mediation could also come from ASEAN or a trusted, neutral actor within the region like Singapore. Parties could also call for an emergency session of the UN Security Council to negotiate a cease-fire, although China’s seat on the council could limit the effectiveness of this option. In the East China Sea, bilateral management of the dispute is the likely first option, with Beijing and Tokyo sitting down to negotiate a common guideline for handling the conflict and preventing its escalation.


Despite extensive trade ties, the parties to the dispute could respond to a rise in tensions by imposing economic sanctions. In response to a Chinese action, for instance, Washington could sanction financial transactions, the movement of some goods and services, and even travel between China and the United States. In retaliation, Beijing could bar U.S. exports and cut back on its extensive purchases of U.S. Treasuries. Claimants could also manipulate exports and relaunch boycotts of goods. Some signals of such a response have already been seen: in 2012 Chinese protesters launched a wave of boycotts of Japanese-branded products. Japan also accused China of halting exports of rare earth minerals after a territorial spat in 2010—a charge Beijing denied—causing a commodities crisis for resource-dependent Japan.


If confrontation were to involve Japan in the East China Sea or the Philippines in the South China Sea, the United States would be obligated to consider military action under defense treaties. Experts note that Washington’s defense commitments to Tokyo are stronger than those to Manila. Under its treaty obligations, the United States would have to defend Japan in the case of an armed attack; the U.S.-Philippine treaty holds both nations accountable for mutual support in the event of an “armed attack in the Pacific Area on either of the Parties.” Military action would represent a last resort, and would depend on the scale and circumstances of the escalation. In the event of armed conflict breaking out between China and Japan, the United States could also use crisis communication mechanisms outlined in the U.S.-China Military Maritime Consultative Agreement (PDF) to encourage a stand-down of forces and facilitate communication between Tokyo and Beijing. Verbal declarations that communicate the seriousness of the dispute and convey support for an ally, as well as offers of military assistance, can also serve as essential “coercive de-escalation” measures during a crisis.

This is the future we seek in the Asia-Pacific—security, prosperity and dignity for all ... let there be no doubt: in the Asia-Pacific in the twenty-first century, the United States of America is all in.

U.S. President Barack Obama



Shen Dingli

Professor of International Relations, Fudan University

Elizabeth Economy

C.V. Starr Senior Fellow and Director for Asia Studies, CFR

Richard Haass

President, CFR

Joshua Kurlantzick

Senior Fellow for Southeast Asia, CFR

Sheila A. Smith

Senior Fellow for Japan Studies, CFR

Simon Tay

Chairman, Singapore Institute of International Affairs



Stirring Up The South China Sea: Regional Responses (July 2012)

This report from the International Crisis Group profiles regional positions in the South China Sea dispute, outlining each claimants’ relationship with China.

Cooperation from Strength: The United States, China and the South China Sea (January 2012)

Regional expert Patrick Cronin and other scholars discuss diplomacy, security, resources and Washington’s role in the South China Sea in this Center for a New American Security report.

Japan and the South China Sea: Forging Strategic Partnerships in a Divided Region (January 2013)

This Institut Français des Relations Internationales paper discusses Japan’s deepening engagement with Southeast Asia.

Making Process, Not Progress: ASEAN and the Evolving East Asian Regional Order (Summer 2007)

This article details ASEAN’s checkered history as a regional group.

The Challenge of Revisionism: The Expanding Role of China’s Non-Military Maritime Vessels (February 2013)

This report from the Center for a New American Security examines the role of China’s maritime agencies in destabilizing the region.

A Game of Shark and Minnow (October 2013)

This New York Times presentation profiles a Filipino ship in the Reed Bank and highlights the ongoing conflict in the South China Sea.


China’s Maritime Disputes in the East and South China Seas (April 2013)

This congressional testimony by Michael Swaine of the Carnegie Endowment for International Peace addresses the origins and drivers of China’s maritime disputes and provides a timeline of major events.

Dangerous Waters: China-Japan Relations on the Rocks (April 2013)

The International Crisis Group’s report on the Diaoyu/Senkaku dispute delves into the history and perspectives of the conflict, and outlines the challenges of crisis mitigation.

Legitimacy and the Limits of Nationalism: China and the Diaoyu Islands (Winter 1998–1999)

This article discusses the role nationalism has played in China’s territorial dispute in the East China Sea.

The 1951 San Francisco Peace Treaty with Japan and the Territorial Disputes in East Asia (January 2002)

This paper article details some of the historical complexities of the Diaoyu/Senkaku Islands disputes during the postwar period.

As China Meets the Southern Sea Frontier: Ocean Identity in the Making, 1902-1937 (Fall 2005)

This paper delves into China’s historical approach to the South China Sea region and its rise in strategic significance.

50 Years from San Francisco: Re-Examining the Peace Treaty and Japan’s Territorial Problems (Autumn 2001)

This paper discusses Japan’s territorial claims on the East China Sea through a historical lens.

The Paracels: the ‘Other’ South China Sea Dispute (July 2001)

This paper examines the Paracel dispute between China and Vietnam and its impact on Sino-Vietnamese relations.

By the Numbers

South China Sea (February 2013)

This U.S. Energy Administration report provides data on resources in the South China Sea.

Economic Outlook (June 2013)

This OECD database offers statistics for economic projections and outlooks.

Trends in World Military Expenditure, 2012 (April 2013)

Independent institute SIPRI maps trends in global military expenditures in this report.


This ASEAN resource provides a range of statistics for the region.

Policy Options

Armed Clash in the South China Sea (April 2012)

This CFR Contingency Planning Memorandum by regional expert Bonnie Glaser examines the risk of armed conflict in the South China Sea.

A Sino-Japanese Clash in the East China Sea (April 2013)

This CFR Contingency Planning Memorandum by Senior Fellow Sheila Smith discusses options to reduce tensions between China and Japan in the East China Sea.

Flashpoints: The Way Forward in the East and South China Seas (March 2013)

Center for New American Security expert Patrick Cronin discusses the deteriorating security environment in the East and South China Seas in this report.



The Association of Southeast Asian Nations. The ten-member regional group includes Indonesia, Malaysia, the Philippines, SIngapore, Thailand, Brunei, Myanmar, Cambodia, Laos, and Vietnam.


The Declaration on Conduct of Parties in the South China Sea. A code of conduct signed by China and the ten ASEAN states that seeks to create guidelines for resolution of territorial disputes.


Exclusive Economic Zone. A zone adjacent to the territorial sea, not extending beyond two hundred nautical miles from the nation’s baseline, where a state has rights to govern its resource and economic development.


Japanese Maritime Self-Defense Force. Its naval fleets maintain control of the country’s sea lanes and patrol territorial waters, including those in the East China Sea.


The People’s Liberation Army of the People’s Republic of China. As the principal body of China’s armed forces, the PLA comprises the Army, Navy, Air Force, and Second Artillery Force.


United Nations Convention on the Law of the Sea. The resolution defines rights and responsibilities of nations in their use of surrounding waters based on exclusive economic zones.


These discussion questions, essay questions, activities and assignments, and supplementary resources are designed to help educators use the “China's Maritime Disputes” InfoGuide in the classroom through an active, learner-centered approach.

Discussion Questions

Ideas for questions to use in facilitating full-class discussions, assigning small group discussion topics, or posting on a class discussion board. Questions allow students to critically reflect on the material provided in the InfoGuide and hone their communication skills.

Essay Questions

Suggestions for essay topics that enable students to dive deeper into the material found in the InfoGuide and conduct their own research and analysis.

Activities and Assignments

In-class activity ideas and homework assignments based on “China’s Maritime Disputes” that promote participatory learning and critical thinking. These can be adapted based on students’ levels and classroom needs. For high school teachers, these activities are accompanied by a list and description of the Common Core State Standards they meet.