South China Sea


Territorial Dispute In The South China Sea


Recent Developments

On July 12, 2016, the Permanent Court of Arbitration in The Hague issued its ruling on a claim brought against China by the Philippines, ruling in favor of the Philippines on almost every count. While China is a signatory to the UN Convention on the Law of the Sea, which established the tribunal, it refuses to accept the court’s authority.

Territorial and jurisdictional disputes in the South China Sea continue to strain relations between China and other countries in Southeast Asia, risking a military escalation. To protect its political, security, and economic interests in the region, the United States has challenged China’s assertive territorial claims and land reclamation efforts by conducting freedom of navigation operations and bolstering support for Southeast Asian partners.

In recent years, satellite imagery has shown China’s increased efforts to reclaim land in the South China Sea by physically increasing the size of islands or creating altogether new islands. In addition to piling sand onto existing reefs, China has constructed ports, military installations, and airstrips—particularly in the Spratly Islands.


China’s sweeping claims of sovereignty over the sea—and the sea’s alleged 11 billion barrels of untapped oil and 190 trillion cubic feet of natural gas—have antagonized competing claimants Malaysia, Vietnam, Brunei, Taiwan, Indonesia, and the Philippines. As early as the 1970s, countries began to claim as their own islands and various zones, such as the Spratly islands, in the South China Sea, which may possess rich natural resources and fishing areas.

China maintains that under international law, foreign militaries are not able to conduct intelligence gathering activities, such as reconnaissance flights, in its exclusive economic zone (EEZ). According to the United States, countries should have freedom of navigation through EEZs in the sea and are not required to notify claimants of military activities. China’s claims threaten sea lines of communication, which are important maritime passages that facilitate trade and the movement of naval forces. In response to China’s assertive presence in the disputed territory, Japan sold military ships and equipment to the Philippines and Vietnam in order to improve their maritime security capacity and to deter Chinese aggression.

In recent years, China has built three airstrips on the contested Spratly Islands to extend its presence in disputed waters, and militarized Woody Island by deploying fighter jets, cruise missiles, and a radar system. China has warned its Southeast Asian neighbors against drilling for oil and gas in the contested region, which has disrupted other nations’ oil exploration and seismic survey activities. To challenge China’s claims in international waters, the United States has occasionally deployed destroyer ships on freedom of navigation operations in the South China Sea to promote freedom of passage.


The United States, which maintains important interests in ensuring freedom of navigation and securing sea lines of communication, has expressed support for an agreement on a binding code of conduct and other confidence-building measures. The United States has a role in preventing military escalation resulting from the territorial dispute. However, Washington’s defense treaty with Manila could draw the United States into a China-Philippines conflict over the substantial natural gas deposits in the disputed Reed Bank or the lucrative fishing grounds of the Scarborough Shoal. A dispute between China and Vietnam over territorial claims could also threaten the military and commercial interests of the United States. The failure of Chinese and Southeast Asian leaders to resolve the disputes by diplomatic means could undermine international laws governing maritime disputes and encourage destabilizing arms buildups.

A Visual Exploration Of The Conflict


South China Sea Interactive Map

Maritime Awareness Project 

A Line In The Sea: How The Philippines Decision Could Settle The South China Sea 

Robert A. Manning James Przystup

Foreign Affairs

August 10, 2016

Parting The South China Sea: How To Uphold The Rule Of Law 

Mira Rapp-Hooper 

Foreign Affairs

September/October 2016

China’s New Spratly Island Defenses

Asian Maritime Transparency Initiative 

December 13, 2016

Beijing Strenghtens Control Over The South China Sea As Its Last Rival Goes Soft

Ralph Jennings 


January 16, 2017

Crunch Time For Washington And Beijing In The South China Sea 

Dan De Luce and Keith Johnson

Foreign Policy 

February 17, 2017

Philippines v. China Arbitration: Be Careful What You Wish For

Sourabh Gupta

Center for Strategic and International Studies 

March 17,2017