February 23, 2017
South China Sea Disputes: Background and U.S. Policy
Overview
commerce transits the SCS each year, including energy
Tensions in the South China Sea (SCS) have become a
supplies to U.S. allies Japan and South Korea. According to
pressing challenge for U.S. policymakers in recent years,
the U.S. Energy Information Administration, the SCS
raising questions for Congress about U.S. goals and strategy
contains about 11 billion barrels of oil rated as proved or
in the Asia-Pacific region. The heavily trafficked SCS is
probable reserves—a level similar to the amount of proved
home to sovereignty disputes among Brunei, the People’s
oil reserves in Mexico—and 190 trillion cubic feet of
Republic of China (PRC), Malaysia, the Philippines,
natural gas. The SCS is also among the largest sources of
Taiwan, and Vietnam. (Japan has other disputes with China
fish for the countries surrounding it, and it contains
and Taiwan in the East China Sea.) The United States has
significant coral and other undersea resources.
no territorial claim in the South China Sea and does not
take a position on the sovereignty of any of the geographic
Figure 1. The South China Sea
features in the SCS, but has urged that disputes be settled
without coercion and on the basis of international law.
Separate from the sovereignty disputes, the United States
and China have a long-simmering disagreement over the
right of foreign militaries to operate in waters near China,
including in the South China Sea. The disagreement has led
to incidents between Chinese and U.S. ships and aircraft in
international waters and airspace.
Since 2013, the sovereignty disputes and the U.S.-China
dispute over freedom of the seas for military ships and
aircraft have both been at play in the controversy over
China’s moves to build artificial islands with military
installations on disputed features in the SCS’ Spratly
Islands. Of particular concern to the U.S. military is the
possibility that China’s island building may be part of an
effort to dominate the South China Sea, with the ultimate
goal of making China a regional hegemon that can set the
rules by which other regional actors must operate. A long-
standing goal of U.S. grand strategy has been to prevent the

emergence of a regional hegemon in Eurasia. U.S. and
Source: CRS graphic
regional observers have been alert to other actions China
The Sovereignty Disputes
might take to achieve dominance in the SCS, including
initiating reclamation on another SCS landmass, such as
Beijing states that it has “indisputable sovereignty over the
Scarborough Shoal, or declaring an Air Defense
South China Sea islands and their adjacent waters,” without
Identification Zone (ADIZ) over parts of the SCS.
defining “adjacent waters.” On maps, China depicts its
claims with a “nine-dash line” that, if connected, would
President Trump’s first statements as president on Asian
enclose an area covering approximately 90% of the sea.
maritime disputes and the South China Sea came in a
Beijing has never explained definitively what the line
February 10, 2017, joint statement with visiting Japanese
signifies. In the northern part of the sea, China, Taiwan, and
Prime Minister Shinzo Abe. The two leaders said their
Vietnam contest sovereignty of the Paracel Islands; China
countries are committed to “maintaining a maritime order
has occupied them since 1974. In the southern part of the
based on international law, including freedom of navigation
sea, China, Taiwan, and Vietnam claim all of the
and overflight and other lawful uses of the sea.” They said
approximately 200 Spratly Islands, while Brunei, Malaysia,
their countries “oppose any attempt to assert maritime
and the Philippines, a U.S. treaty ally, claim some of them.
claims through the use of intimidation, coercion or force,”
Vietnam controls the greatest number of Spratly features. In
and called on “countries concerned to avoid actions that
the eastern part of the sea, China, Taiwan, and the
would escalate tensions in the South China Sea, including
Philippines all claim Scarborough Shoal; China has
the militarization of outposts, and to act in accordance with
controlled it since 2012. China’s “nine-dash line” and
international law.”
Taiwan’s similar “eleven-dash line” overlap with the 200-
nautical-mile (nm) Exclusive Economic Zones (EEZs) that
Key Facts
five Southeast Asian nations—Brunei, Indonesia, Malaysia,
The SCS is one of the world’s most heavily trafficked
the Philippines, and Vietnam—claim under the 1994 United
waterways. An estimated $5.3 trillion in ship-borne
Nations Convention on the Law of the Sea (UNCLOS).
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South China Sea Disputes: Background and U.S. Policy
The U.S.-China Dispute Over Freedom
in the SCS, but has not used its artificial islands in such
of the Seas
operations.
A dispute over how to interpret UNCLOS lies at the heart
of tensions between China and the United States over the
In 2013, the Philippines sought arbitration under UNCLOS
activities of U.S. military vessels and planes in and over the
over Chinese behavior in the SCS. In July 2016, an
South China Sea and other waters off China’s coast. China,
UNCLOS arbitral tribunal ruled that China’s nine-dash line
Vietnam, Malaysia, Brunei, and the Philippines are all
claim had “no legal basis.” It also ruled that none of the
parties to UNCLOS. The United States is not, but has long
land features in the Spratlys is entitled to any more than a
had a policy of abiding by UNCLOS provisions relating to
12-nm territorial sea; three of the Spratlys features that
maritime disputes and rights. UNCLOS allows state parties
China occupies generate no entitlement to maritime zones;
to claim 12-nm territorial seas and 200-nm EEZs around
and China violated the Philippines’ sovereign rights by
their coastlines and around “naturally formed” land features
interfering with Philippine vessels, and by damaging the
that can “sustain human habitation.” Rocks that are above
maritime environment and engaging in reclamation work on
water at high tide but not habitable generate territorial seas
a feature in the Philippines’ EEZ. The United States has
but not EEZs.
urged China and the Philippines to abide by the ruling,
which under UNCLOS is binding on both parties. China,
The United States and most other countries interpret
however, has declared the ruling “null and void.” Philippine
UNCLOS as giving coastal states the right to regulate
President Rodrigo Duterte, who took office just before the
economic activities within their EEZs, but not the right to
tribunal’s ruling, has not sought to enforce it. The
regulate navigation and overflight through the EEZ,
Philippines has signaled that it is focused on pursuing a
including by military ships and aircraft. China’s position is
Code of Conduct between China and the Association of
that UNCLOS allows it to regulate both economic activity
Southeast Asian Nations (ASEAN). The Philippines holds
and foreign militaries’ navigation and overflight through its
the rotating chairmanship of ASEAN for 2017.
EEZ. China objects strenuously to U.S. survey and ocean
surveillance operations in its EEZ, and to U.S. freedom of
U.S. Actions
navigation operations (FONOPs) and patrols near disputed
In response to the situation in the SCS, the United States
features it controls. China says it “respects the freedom of
has taken steps to improve the ability of the Philippines and
navigation and overflight” under international law, but
Vietnam to maintain maritime domain awareness (MDA)
opposes “relevant countries threatening and undermining
and patrol their EEZs, part of a DOD five-year $425 million
the sovereignty and security of coastal states under the
Southeast Asia Maritime Security Initiative announced in
pretext of such freedom.” In 2016, Chinese Foreign
May 2015. The United States has taken steps to strengthen
Minister Wang Yi summed up China’s position as,
U.S. security cooperation with Japan, Indonesia, Malaysia,
“Freedom of navigation does not equal the freedom to run
the Philippines, Singapore, and Vietnam; expressed support
amok.” On February 4, 2017, Secretary of Defense Jim
for the idea of Japanese patrols in the SCS; and stated that
Mattis stated, “freedom of navigation is absolute, and
the United States would support a multinational maritime
whether it be commercial shipping or our U.S. Navy, we
patrol of the SCS by members of ASEAN. The U.S. Navy
will practice in international waters and transit international
has conducted FONOPs in the SCS, challenging maritime
waters as appropriate.” In proposed amendments to its 1984
claims by Asian countries that the United States considers
Maritime Traffic Safety Law announced in February 2017,
to be excessive, and has regularly sent single or dual carrier
China also appears to be seeking to tighten rules for foreign
strike groups into the sea. The USS Carl Vinson strike
vessels operating in its territorial sea.
group began “routine operations” in the SCS in February
2017. Issues for Congress include whether U.S. actions
China’s Artificial Island Building
have been appropriate and effective, and whether the
Since 2013, China has undertaken extensive land
United States should take different or additional actions.
reclamation and construction in the Spratly Island chain in
the SCS. According the U.S. Department of Defense
Action in the 114th Congress
(DOD), China’s reclamation has created over 3,200 acres (5
In the 114th Congress, the National Defense Authorization
square miles) of artificial landmasses on the seven reefs that
Act (NDAA) for FY2016 (P.L. 114-92) authorized the
China controls. China portrays its actions as part of an
South China Sea Initiative. The NDAA for FY2017 (P.L.
effort to play catch-up to other claimants, several of which
114-328) re-designated it the Southeast Asia Maritime
control more Spratlys features and carried out earlier
Security Initiative and required DOD to describe China’s
reclamation and construction work on them, although
activities in the SCS in an annual report to Congress on
China’s reclamation work has been far greater in scale.
China’s military. The Senate agreed to S.Res. 153,
Since 2015, China has built facilities with potential military
supporting U.S.-Japan cooperation the SCS. Other
uses on the artificial islands, including three airstrips—two
legislation related to the SCS considered by the 114th
more than 10,000-feet-long and one nearly 9,000-feet-
includes S. 2865 and H.R. 5890, S. 3509, S.Res. 183,
long—hangars that could shelter fighter jets, harbors, anti-
S.Res. 370, and S.Res. 526 and H.Res. 830.
aircraft batteries, radars, and structures that could house
surface-to-air missiles. An April 2016 DOD report judged
Ben Dolven, Specialist in Asian Affairs
that China would be able to use its new artificial islands “as
Susan V. Lawrence, Specialist in Asian Affairs
persistent civil-military bases to enhance its long-term
Ronald O'Rourke, Specialist in Naval Affairs
presence in the South China Sea significantly.” China has
undertaken military training exercises and bomber patrols
IF10607
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South China Sea Disputes: Background and U.S. Policy


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https://crsreports.congress.gov | IF10607 · VERSION 2 · NEW

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