
Territorial Disputes in the South China Sea
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Asia
Critical
Worsening
Territorial Dispute
Recent Developments
Tensions between China and both the Philippines and Vietnam have recently cooled, even as China increased its military activity in the South China Sea by conducting a series of naval maneuvers and exercises in March and April 2018. Meanwhile, China continues to construct military and industrial outposts on artificial islands it has built in disputed waters.
The United States has also stepped up its military activity and naval presence in the region in recent years, including freedom of navigation operations (FONOPs) in January and March 2018. In a speech during his November 2017 visit to Southeast Asia, President Donald J. Trump emphasized the importance of such operations, and of ensuring free and open access to the South China Sea. Since May 2017, the United States has conducted six FONOPs in the region.
Background
China’s sweeping claims of sovereignty over the sea—and the sea’s estimated 11 billion barrels of untapped oil and 190 trillion cubic feet of natural gas—have antagonized competing claimants Brunei, Indonesia, Malaysia, the Philippines, Taiwan, and Vietnam. As early as the 1970s, countries began to claim islands and various zones in the South China Sea, such as the Spratly Islands, which possess rich natural resources and fishing areas.
China maintains [PDF] 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, claimant countries, under UN Convention of the Law of the Sea (UNCLOS), should have freedom of navigation through EEZs in the sea and are not required to notify claimants of military activities. In July 2016, the Permanent Court of Arbitration at The Hague issued its ruling on a claim brought against China by the Philippines under UNCLOS, ruling in favor of the Philippines on almost every count. While China is a signatory to the treaty, which established the tribunal, it refuses to accept the court’s authority.
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 new islands altogether. In addition to piling sand onto existing reefs, China has constructed ports, military installations, and airstrips—particularly in the Paracel and Spratly Islands, where it has twenty and seven outposts, respectively. China has militarized Woody Island by deploying fighter jets, cruise missiles, and a radar system.
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 FONOPs and bolstering support for Southeast Asian partners. Also in response to China’s assertive presence in the disputed territory, Japan has sold military ships and equipment to the Philippines and Vietnam in order to improve their maritime security capacity and to deter Chinese aggression.
Concerns
The United States, which maintains important interests in ensuring freedom of navigation and securing sea lines of communication (SLOCs), has expressed support for an agreement on a binding code of conduct and other confidence-building measures. China’s claims threaten SLOCs, which are important maritime passages that facilitate trade and the movement of naval forces.
The United States has a role in preventing military escalation resulting from the territorial dispute. Washington’s defense treaty with Manila could draw the United States into a potential China-Philippines conflict over the substantial natural gas deposits or lucrative fishing grounds in disputed territory. The failure of Chinese and Southeast Asian leaders to resolve the disputes by diplomatic means could also undermine international laws governing maritime disputes and encourage destabilizing arms buildups.
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Territorial Disputes in the South China Sea

Territorial Disputes in the South China Sea








Background Articles
Pham Ngoc Minh Trang Diplomat October 22, 2019
Asia Maritime Transparency Initiative September 26, 2019
Ronald O'Rourke Congressional Research Service September 24, 2019
James Pearson and Khanh Vu Reuters August 23, 2019
Mark Manantan Diplomat August 5, 2019
Greg Polling Center for Strategic and International Studies July 24, 2019
Ankit Panda South China Morning Post July 14, 2019
Asia Maritime Transparency Initiative July 11, 2019
Jason Gutierrez and Hannah Beech New York Times June 13, 2019
Asia Maritime Transparency Initiative May 20, 2019
Demetri Sevastopulo and Kathrin Hille Financial Times April 28, 2019
Scott N. Romaniuk and Tobias Burgers Diplomat March 20, 2019
Chris Horton and Cliff Venzon Nikkei Asian Review March 16, 2019
South China Morning Post February 16, 2019
Congressional Research Service January 31, 2019
Greg Poling and Bonnie S. Glaser Foreign Affairs January 22, 2019
Andrew Chubb Brookings Institution January 22, 2019
Center for Strategic and International Studies October 2018
Ivan Watson, Brad Lendon, and Ben Westcott CNN August 2018
Steven Lee Myers New York Times August 29, 2018
Bonnie S. Glaser and Gregory Poling Foreign Affairs June 5, 2018
Jin Wu, Simon Scarr, and Weiyi Cai Reuters May 24, 2018
Liza Tobin War on the Rocks May 9, 2018
Collin Koh South China Morning Post April 7, 2018
Ngo Minh Tri Center for Strategic and International Studies April 2, 2018
Leslie Fong South China Morning Post March 29, 2018
Hong Thao Nguyen and Binh Ton-Nu Thanh Maritime Awareness Project March 8, 2018
Frances Mangosing Inquirer February 5, 2018
Gregory Poling Foreign Affairs January 25, 2018
Hal Brands and Zack Cooper Defense One December 21, 2017
Ankit Panda The Diplomat October 12, 2017
Ralph Jennings Voice of America October 4, 2017
Joe Cochrane New York Times September 10, 2017
Gordon Lubold and Jeremy Page Wall Street Journal September 1, 2017
Hunter Marston Foreign Affairs August 15, 2017
Asia Maritime Transparency Initiative
Prashanth Parameswaran The Diplomat August 1, 2017
Bill Hayton Foreign Policy July 31, 2017
Lynn Kuok Foreign Affairs July 21, 2017
American Interest July 6, 2017
Benoit Hardy-Chartrand and J. Berkshire Miller National Interest June 27, 2017
Dan De Luce and Keith Johnson Foreign Policy May 25, 2017
Mira Rapp-Hooper and Charles Edel Foreign Affairs May 18, 2017
Helene Cooper New York Times May 2, 2017
Reuters May 2, 2017
Oliver Holmes Guardian April 5, 2017
Pete Cobus Voice of America
Dan De Luce and Keith Johnson Foreign Policy February 17, 2017
Ralph Jennings Forbes January 16, 2017
Asia Maritime Transparency Initiative December 13, 2016
Evelin Danubrata Reuters October 6, 2016
Mira Rapp-Hooper Foreign Affairs September/October 2016
Robert A. Manning and James Przystup Foreign Affairs August 10, 2016
New York Times August 8, 2016
CNN July 12, 2016
Maritime Awareness Project
Jim Della-Giacoma IPI Global Observatory June 9, 2016
Tom Benner Al-Jazeera June 5, 2016
Jane Perlez and Yufan Huang New York Times May 5, 2016
William G. Frasure The Diplomat May 3, 2016
Conor Cronin Center for Strategic & International Studies April 28, 2016
Simon Denyer The Washington Post April 12, 2016
Derek Watkins New York Times
The Economist March 26, 2016
Mira Rapp-Hooper Foreign Affairs March 21, 2016
Sourabh Gupta Center for Strategic and International Studies March 17, 2016
Jonathan G. Odom The Diplomat March 9, 2016
International Crisis Group January 26, 2016
Latest CFR Analysis
Oriana Skylar Mastro Contingency Planning Memorandum May 21, 2020
Oriana Skylar Mastro CFR Blog, “Strength Through Peace” May 20, 2020
Center for Preventive Action CFR Blog, "Strength Through Peace" January 14, 2019
CFR InfoGuide
CFR Asia Program May 23, 2018
Ely Ratner CFR Policy Innovation Memorandum April 6, 2018
Ely Ratner Foreign Affairs July/August 2017
Ely Ratner The Interpreter June 28, 2018
Ely Ratner CFR Blog, "Asia Unbound" June 20, 2017
Jennifer M. Harris Newsweek July 17, 2016
Stewart Patrick CFR Blog, "The Internationalist" April 12, 2016
Robert D. Blackwill and Kurt M. Campbell CFR Council Special Report February 2016
Joshua Kurlantzick CFR Contingency Planning Memorandum September 2015
Karen Brooks CFR Expert Brief August 4, 2015
Bonnie S. Glaser CFR Contingency Planning Memorandum Update April 2015
Beina Xu CFR Backgrounder
Robert D. Blackwill and Ashley J. Tellis, Council Special Report April 2015
Matthew C. Waxman Asia Maritime Transparency Initiative January 21, 2015
Primary Sources
U.S. House Permanent Select Committee on Intelligence May 17, 2018
Donald Trump The White House November 15, 2017
Jim Mattis U.S. Department of Defense June 3, 2017
Permanent Court of Arbitration July 12, 2016
U.S. Department of Defense
U.S. Energy Information Administration
Ash Carter U.S. Department of Defense May 27, 2015
State Council Information Office of the People's Republic of China U.S. Naval Institute News May 2015
U.S. Department of Defense April 2015
Chinese Ministry of Foreign Affairs December 7, 2014