A Guide to Stepping it Up in the South China Sea


The South China Sea has become one of the most dangerous flashpoints in the world as China continues to aggressively expand its influence and capabilities there. One year ago, we proposed several ways in which the United States could try to deter further Chinese encroachments. But, as the recent Shangri-La Dialogue demonstrated, tensions in the region have only risen since then. The Chinese have only accelerated their bellicose behavior, and nothing the United States has done has seemed to have any effect. The United States and its partners now have no choice but to consider a wider range of more assertive responses.

We are not seeking a conflict with China, nor do we advocate a war. We do not believe that China is an inevitable adversary of the United States.  But we are increasingly concerned that Chinese actions in the South China Sea, if left unopposed, will give it de facto dominance of an area that is a vital strategic interest to the United States. More direct U.S. actions would involve significant risks — but so would failing to act, and those risks are far less appreciated.

Why does the South China Sea matter?  It is one of the world’s most important shipping lanes, transited by about one-third of global commercial goods each year. It lies atop at least seven billion barrels of oil and an estimated 900 million cubic feet of natural gas. Conflicting claims to these important waters abound. These involve several U.S. allies and friends and will likely be exacerbated by the pending outcome of an international court case between China and the Philippines. Chinese efforts to establish sovereign claims over these key international waters not only threaten unimpeded access to global shipping lanes and U.S. partners in the region, but also set a dangerous global precedent. Beijing’s forceful efforts are intended to establish regional hegemony by creating a zone of “near seas” over which it can claim sole control.

During the past year, Chinese actions have grown bolder. They have completed land reclamation efforts at the three largest outposts in the South China Sea and are now focusing on developing infrastructure. Each one already has an airfield with a 9,800-foot runway, which is long enough to land most military aircraft. They have also landed a military jet on Fiery Cross Reef and deployed advanced fighters and surface-to-air missiles on Woody Island in the Paracels. Taken together, these capabilities provide forward-positioned power projection platforms for Chinese fighters, bombers, and reconnaissance aircraft. Aircraft from these bases could easily reach — and possibly enforce — Chinese claims out to the so-called “nine-dash line” that borders the easternmost rim of the South China Sea. Chinese Navy ships and maritime militia can also use these outposts as refueling and provisioning stops that extend their sea presence across this vast expanse. U.S. aircraft carriers are at best transient visitors in these same waters, and no other country in the region can project and sustain the air and naval presence in the South China Sea that these fixed bases now offer.

The United States has responded to this continued expansion with ever stronger warnings and actions. Most notably, the United States conducted its first freedom of navigation operation (FONOP) in the South China Sea in October 2015, when a U.S. destroyer sailed within 12 miles of Subi Reef to demonstrate that the United States rejects any Chinese maritime claims emanating from its artificial islands. At least two other FONOPs have been conducted since then, and the head of U.S. Pacific Command, Admiral Harry Harris, has stated that future FONOPs will increase in number, scope, and complexity.

Yet Chinese confrontational actions are nevertheless continuing and even escalating. In recent months, for example, Chinese fighter jets have flown dangerously close to U.S. reconnaissance aircraft in both the South and East China Seas, violating an agreement that the United States and China signed last year on safe conduct in the air. And the Chinese government recently announced that it is considering establishing an Air Defense Identification Zone (ADIZ) over the South China Sea as a further signal of its security claims to this key region.

China has subtly but forcefully established a permanent presence across a series of outposts on territory that did not exist five years ago. This is the new reality of the South China Sea. As a result, the United States and its regional partners now have little choice but to consider a broader and stronger range of options. These actions should be designed to achieve two primary objectives: to deter China from further expansion and combative behaviors and to better position the United States and its partners for military action to defend the international commons, if required.

We readily acknowledge that these objectives may conflict with each other, and that more options risk provoking precisely the type of conflict that the United States seeks to avoid. But failing to take stronger action also runs the very serious risk that the Chinese will gradually but inevitably gain control of this critical maritime region. That would weaken the regional position of U.S. allies and partners, but even more importantly, it would challenge the vital and longstanding U.S. interest in maintaining global freedom of navigation.

We suggest six options that the United States and its partners should now consider, listed in increasing order of assertiveness.

1. Enhance and expand maritime transparency in the South China Sea. The United States and its partners must redouble efforts to make clear that the South China Sea is an international waterway open to all. The new Maritime Security Initiative is a step in the right direction that should be continued and, over time, expanded. Washington and its partners should also promote greater transparency about Chinese maritime militias, which have been used as irregular military forces that operate in the gray zone. The United States should also help improve regional maritime domain awareness to facilitate navigation, safe transit, search and rescue, and natural disaster response. These steps would reinforce the essential premise that this huge maritime domain is a vital element of the global commons, not a national preserve.

2. Continue to increase U.S. military support and presence in the Philippines. Joint U.S.-Philippine military cooperation and exercises are now at levels not seen since the U.S. departure from Subic Bay and Clark Air Force Base in the early 1990s. The two countries started conducted joint naval patrols in March, and Secretary of Defense Ash Carter announced in April that the United States would rotate troops and combat aircraft to the Philippines in the future. The next step could be a robust exercise program that demonstrates bilateral military strength. The U.S. Marines and their Philippine counterparts could practice landings on Palawan Island, an area that abuts China’s nine dash line. The U.S. Army could demonstrate its abilities to rapidly deploy from U.S. bases to establish missile defense sites and expeditionary logistics nodes on remote Philippine islands, while the U.S. Air Force could expand air defense exercises and base dispersal options with the Philippine air force. They could also continue improving base infrastructure that both countries could use during a conflict, including hardened aircraft shelters, upgraded dispersal airfields, protected munitions storage, and prepared air and missile defense locations.

A more controversial option would be for the United States to announce that its mutual defense treaty with the Philippines includes the disputed Scarborough Shoal — similar to its 2014 announcement that the disputed Senkaku islands fell within the defensive perimeter of the U.S.-Japan security alliance. This would strengthen the U.S. commitment to defend its allies against Chinese encroachment, but might unintentionally promote more provocative behavior by the Philippines.

3. Strengthen the U.S. military relationship with Vietnam. Bilateral relations have warmed dramatically in recent years. President Obama lifted the longstanding U.S. arms embargo in May, and recent U.S. military port visits signal the beginning of a closer military relationship. The United States could seek expanded opportunities to exercise air and land capabilities with the Vietnamese, including the use of airbases and port facilities. The United States could also sell Vietnam fourth-generation F-16 or F/A-18 fighters, which would significantly improve its air defense capabilities and might prove a potent deterrent. These steps could improve long-term prospects for access, overflight, and perhaps even rotational basing of U.S. ships, aircraft, or other forces.

4. Sustain a significant U.S. and international Coast Guard presence in the South China Sea. Beijing has masterfully employed commercial and coast guard-like vessels to advance its claims and intimidate its regional neighbors in the South China Sea for years, which has helped it avoid the international military response that naval ships might provoke. The United States and its partners could counter these tactics by establishing a regular and visible coast guard presence. Only the United States has a major global coast guard capability, but some regional and even some international partners might be able to assist. As China has demonstrated, Coast Guard vessels are less provocative than warships, and their employment by the United States and partners could confront similar Chinese ships with far less risk of military escalation.

5. Increase U.S. military activity in the South China Sea. The United States periodically patrols the South China Sea with its Nimitz-class carriers, and less frequently, with its large-deck amphibious carriers. The United States could ensure that a carrier strike group or amphibious ready group with power projection capabilities (including marines) remained in the South China Sea for at least six out of every 12 months. The U.S. Air Force could conduct more frequent overflights in the region, including with B-1, B-2, and B-52 bombers. The United States could also increase its surveillance activities over the Chinese-claimed islands, including by flying directly over them at high altitudes (which the United States considers international airspace). Washington could lower the risk of inadvertent military escalation by encouraging international participation and announcing these activities well in advance. This option would not only provide an important signal of U.S. intentions, but would also ensure that a substantial amount of U.S. immediate strike capabilities is available in the event of a conflict that could offset Chinese capabilities based on its artificial islands.

6. Build floating U.S. bases in the South China Sea. The United States could respond to Beijing’s artificial islands by building temporary afloat bases that would sustain a greater U.S. and international presence. It could position one or more Expeditionary Mobile Bases (ESBs, formerly called Afloat Staging Bases) in the South China Sea, which could act as small, mobile floating bases that can project power in a number of ways, including basing helicopters and special operations forces. The United States could also re-energize the development of the long-studied Joint Mobile Offshore Base (JMOB). In the future, a series of JMOBs could serve as mobile forward sea bases (like multiple joined oil platforms) in the region, large enough to support large fixed wing air transports and stationing hundreds or even thousands of troops. The Chinese are assessing this capability as well, but have achieved much the same effect by their island-building program.

The great advantage of ESBs and JMOBs is that they can support a wide range of less provocative non-combat operations, such as maritime domain awareness, search and rescue, counter-piracy, and humanitarian relief. Crewing both platforms with a combination of Coast Guard and civilian sailors — potentially from other countries as well as from the United States — could reduce the risk that China would see this as a stark military escalation. It could provide a valuable dual-use capability for the United States, supporting important missions on a regular basis (including the Coast Guard patrols mentioned above), but also enabling the United States to rapidly improve its regional power projection capabilities in the event of a conflict.

None of these options is perfect; many involve significant risks and tradeoffs and could increase the chance of conflict. Yet continuing with current, ineffective options would also have serious consequences. Left unchecked, within five years Beijing will have a string of bases, airfields, and ports on artificial islands spanning the South China Sea from the coast of Vietnam to the Palawan islands in the Philippines. These outposts will unquestionably be able to serve as springboards for Chinese power projection across the entire region. The United States needs to make tough decisions about whether to accept Chinese actions as a fait accompli, or to counter these actions more strongly. These proposals provide a stating point for a deeper conversation between the United States and its friends and allies in the region about China’s increasing progress toward unimpeded control of the South China Sea.


Lt. General David W. Barno, USA (Ret.) is a Distinguished Practitioner in Residence, and Dr. Nora Bensahel is a Distinguished Scholar in Residence, at the School of International Service at American University. Both also serve as Nonresident Senior Fellows at the Atlantic Council. Their column appears in War on the Rocks every third Tuesday. To sign up for Barno and Bensahel’s Strategic Outpost newsletter, where you can track their articles as well as their public events, click here.

Image: U.S. Navy photo by Ensign Molly Hanna