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What Marines need to know about South China Sea territorial disputes

20 May 2014 | Jen Pearce Marine Corps Base Quantico

The nine-dash-line is an area in the South China Sea that China claims as sovereign territory. It extends from the southern coast of China, down the east coast of Vietnam, to the northwest coast of Sabah and Sarawak, Malaysia, up the entire west coast of the Philippines, and to Taiwan. The history of this line is somewhat debated: Many argue that these claims date back officially to 1935, when the Kuomintang government published an official list of Chinese names for the islands in the South China Sea. Many Chinese, however, refer to a series of maps commissioned during the Qing Dynasty that show the entire area as belonging to China. And some members of the Chinese government argue there is written proof of sovereignty going back several centuries B.C.

All of the countries in this maritime region have overlapping claims with China. Disputes over these waters were infrequent until 1991, when China invoked international law to claim it as sovereign territory. In 2011, the United States officially condemned China’s use of force in the South China Sea, and from that point forward, the number of skirmishes in this maritime region have increased.

Oil reserves in the sea are estimated to be in the billions of barrels. Fishing accounts for a large percentage of the region’s GDP, with nearly a tenth of the world’s fishing stock found in this small area. Furthermore, fish accounts for approximately 20-50 percent of the protein intake in Southeast Asia. Perhaps most important to the United States, however, is that maritime trade has doubled every year since 1945, and three out of the 20 busiest ports in the world are in the South China Sea. Oil tankers originating in the Middle East, headed for the United States, pass through the Strait of Malacca and out to the Pacific.

China’s attempt to exert control within its nine-dash line has the potential to affect American interests because conflict in that region can impact freedom of navigation for trade and military vessels. It also threatens the right of countries, including the U.S., to exploit the mineral and fish resources outside of legitimate Exclusive Economic Zones. Furthermore, the U.S. is bound to defend the Philippines under a mutual defense treaty.

Any perceived military preemptive action might cause a situation to escalate very quickly. This was the case in 2009 when the USNS Impeccable was confronted by five People’s Liberation Army Navy assets and forced to take emergency action to avoid a collision. As part of a deterrent strategy, the 2006 Quadrennial Defense Review directed the Navy to position at least six carriers and 60 percent of its submarines in the Pacific “to support engagement, presence and deterrence.”

In 2010, the United States formally named an ambassador to the Association of Southeast Asian Nations to ensure that the United States routinely engages in multi-lateral talks, including those of the ASEAN Regional Forum. President Obama traveled to the region last month and announced the signing by the U.S. and Philippines of a 10-year Enhanced Defense Cooperation Agreement, allowing U.S. forces more access to Philippine bases and to position ships, aircraft, equipment and troops for maritime security.

There are no simple solutions for South China Sea territorial disputes. China’s increasing appetite for resources, combined with its growing military and defense capabilities increase the potential for exertion of force in the region. However, because of the close interdependencies of the countries involved, and because of their individual and collective relationships with the United States, the U.S. must employ a multidisciplinary approach to dealing with the threat, using various levels of hard and soft power. Territorial disputes in the South China Sea are likely to increase in the next decade, and the countries of Southeast Asia will no doubt continue to look to the United States to lead the efforts of protecting and defending mutual interests in the region.

Editor’s note: The views expressed in this article are those of the author and do not necessarily represent the views of, and should not be attributed to, the Center for Operational Culture Learning or the United States Marine Corps. This piece was created at the CAOCL. The center is located on Marine Corps Base Quantico and provides regional, culture and language training programs for Marines of all ranks. For more information about CAOCL please visit

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