Build an Island of Freedom

By Captain Sam J. Tangredi, U.S. Navy (Retired)

More important, PRC has constructed a series of islands on reefs and awash shallows within international waters and within the disputed exclusive economic zones (EEZs) of other nations. These artificial islands have runways and are armed with antiair weapons. There are indications that tunnels for additional weapons and hardened shelters for strike missiles have been and continue to be built. 2 Although a signatory of the United Nations Convention on the Law of the Sea (UNCLOS), the PRC refuses to accept international court decisions concerning its possession and control of these artificial features.

To counter PRC claims and preserve a hope that international law and norms might be maintained in the South China Sea region, the U.S. Navy conducts freedom of navigation (FON) operations in the PRC-claimed waters. FON operations, however, are temporary exercises and no longer appear to have the diplomatic and media effects they had in previous years. 3 FON ops can be conducted within the vicinity of the Paracels or Spratleys and the PRC government loudly will protest, but the reality will not change. 

The United States and its allies must take more a decisive approach to reestablishing law and norms and emplace a mobile offshore base (MOB) to create an “island of freedom” in the South China Sea. A viable position would be on the Macclesfield Bank or in Dangerous Ground to the west of Palawan, Philippines. This MOB—a concept discussed in the late 1990s—could start as a single (inoperative) oil rig manned by a “peace contingent” of U.S. and partner Coast Guardsmen and Department of Defense civilians. Officially it would be an aid to navigation in dangerous ground.

Mobile Offshore Bases

The concept of large mobile offshore bases—as a means of maritime presence and projecting joint forces into a region of crises—gained temporary prominence through the writings of the then-Vice Chairman of the Joint Chiefs of Staff, Admiral Bill Owens, in the mid-1990s. 4 As conceived by Admiral Owens, MOBs (also referred to as Joint Mobile Offshore Bases) would be “built from the experience and technology associated with offshore oil-drilling platforms . . . perhaps we would build them by assembling components that arrive separately in the region of concern.” 5

At the high end, proponents envisioned linked-together oil rig-type platforms (generally self-stabilizing and not bottom-tethered) that could create runways long enough to land C-140, or even C-17 aircraft (6,000-foot length). A table in Admiral Owens’ work compares the envisioned MOB to the size of Reagan National Airport. 6 Whether or not such a floating, non-tethered base could be constructed on that scale, the technology necessary to link several floating oil rig platforms was demonstrated and experiments and studies were conducted (some funded by the Office of Naval Research) that suggested such links—combined with self-positioning propulsion—could prove effective even in challenging sea-states. 7

Like other novel ideas that lose their champions, however, the large-scale MOB idea was quickly shelved following Admiral Owens’ retirement. In truth, critics were correct that a C-17-capable MOB would be expensive (the Institute for Defense Analyses estimated $10 billion) and difficult to defend against an offensive-capable military opponent.8 Several offices in OpNav feared the effect the MOB concept would have on congressional support for future aircraft carriers, and an action officer was directed to publicize the arguments against MOBs. 9 Nevertheless, MOB studies were the origin of the later more popular “sea basing” concept still championed by the Navy. 10

A MOB of Peace

Lost in the criticism of the C-17 runway-sized MOB were offers by offshore oil rig builders McDermott Technologies, Bechtel, Aker Maritime, and Kvaerner Maritime to build smaller, modular MOBs in the $10 million range (2000 year dollars) as test platforms. More than ten years later, still smaller operational bases—known as afloat forward staging bases (AFSBs), led by the ex-USS Ponce (LPD-15/AFSB-1)—have proven their usefulness for special operations forces (SOF). The Navy is now constructing the new USS Lewis B. Puller (ESB-3)-class expeditionary mobile base (formerly mobile landing platform) at approximately $140 million per ship. In late 2017, USS Lewis B. Puller replaced the Ponce in the Persian Gulf.   

To present a less-militarized appearance, an “island of freedom” or “MOB of peace” could consist of a used offshore oil rig maintained in position in a shallow area of the South China Sea in which there is no land above sea level. Potentially, this would require no tethering to the ocean floor. Currently there remains a glut of used offshore oil rigs on the world market, with relatively new models destined for the breakers’ yards. 11 Operational oil rigs and drill ships recently have been auctioned for as low as $65 million, approximately 10 percent of their 2011 assessed value. 12 The platform might need refurnished quarters, helicopter pad, etc., but, by deliberate choice there would be no weapons installed. Costs likely could be contained under $100 million. An oil platform would be preferred over a Lewis B. Puller -class ESB because of greater loitering capability and its non-military association.

Officially the platform would be both an aid to international navigation and an environmental research platform. There would be no actions undertaken that involve military purposes or efforts to exploit resources. Personnel assigned would be appropriate for rescue (such as future refugee “boat people”), international law enforcement and research purposes. Any needed protection would be provided by U.S. warships or cutters operating in the vicinity. Perhaps the platform would be placed under the authority of the U.S. National Air and Oceanic Administration (NOAA). The platform would be towed or lifted in place by commercial assets. To avoid confrontations, this would be done without publicity.

As a sovereign vessel positioned in an area in which there is no exposed land and conducting non-military missions that do not exploit resources considered protected by an EEZ, such a U.S.-owned platform, would be legal under international law. In fact, for the purposes of controlling the narrative, the U.S. government could express interest in turning the platform over to an international organization. That truly would make it an “island of peace.”

The implications, however, are three-fold. First, it would represent the willingness of the United States to act in a relatively non-confrontational manner to repudiate PRC claims to the South China Sea and reestablish the global freedom-of the-seas norm.

Second, it would buttress FON operations with a permanent regional presence. It also would be designed as a bargaining chip: if the PRC is uncomfortable with such a platform emplaced in the South China Sea (and the potential for others), then it could consider down-scoping its presence on the artificial islands. Although critics of FON activities are few (excepting virulent PRC rhetoric), those few attempt to portray FONs as a “militaristic” approach to legitimate diplomacy. This platform would be less so.

Third, it represents a tool for “escalating to deescalate,” a tactic now associated with Russian foreign policy, but which has less nefarious potentials. The United States should restart research and development in MOB technologies, developing the ability to expand the “island of freedom and peace” into an actual military-capable MOB—analogous to what the PRC has done in the Paracels and Spratleys. If the PRC wants to expand its activities to close the South China Sea, the U.S. could expand its activities to keep it open. If the PRC wishes to reduce potential tensions, it could stop constructing artificial islands, demilitarize them, and turn their control over to an international organization.

As a practical outcome, it must be admitted that achieving “one out of the three ain’t bad.”  


1. The most notable appropriation incident was PRC seizure of an ocean glider operated by USNS Bowditch on December 15, 2016. It was returned after several days of examination and media attention. See such reports as Dan Lamothe and Missy Ryan, “Pentagon: Chinese naval ship seized an unmanned U.S. underwater vehicle in the South China Sea,” Washington Post , December 17, 2016, ; Sam LaGrone, “Updated: Chinese Seize U.S. Navy Unmanned Vehicle,” USNI News , December 16, 2016, ; Sam J. Tangredi, “Tax China for Gray-Zone Infractions,” Proceedings Today , May 2017,

2. Asia Maritime Transparency Initiative, “A Constructive Year for Chinese Base Building,” December 14, 2017,

3. An argument that the “consistent practice of free navigation” is as effective (or not) as formal FON operations can be found in Peter A Dutton and Isaac B. Kardon, “Forget the FONOPs—Just Fly, Sail, Operate Wherever International Law Allows,” Lawfare (blog), June 10, 2017,

4. Most notably in Admiral Willam A. Owens, USN, High Seas: The Naval Passage to an Uncharted World (Annapolis, MD: Naval Institute Press, 1995), pp. 162-166.

5. Ibid., pp. 162-163.

6. Ibid., p.165.

7. Studies include: Ronald N. Kostoff, Floating Ocean Platform (Office of Naval Research, c. 1991), ; Anouck R. Girard, et al., An Experimental Testbed for Mobile Offshore Base Control Concepts (University of California at Berkeley, 2001), ; and W.L. Greer, project leader, Mobile Offshore Base Operational Utility and Cost Study , IDA Paper P-3573 (Alexandria, VA: Institute for Defense Analyses, January 2001).

8. [1] Greer, p. 17.

9. [1] Nagy, Paul, “Setting the Record Straight on Mobile Offshore Bases,” National Defense , August 2001, .

10. National Research Council, Sea Basing: Ensuring Joint Force Access from the Sea (Washington, DC: National Academies Press, 2005).  

11. Tom Lamont, “Where Oil Rigs Go to Die,” The Guardian , 2 May 2017, .

12. Irina Slav, “90% Off Sale On Offshore Drilling Rigs?” Oil , May 10, 2016, .

Captain Tangred i is a professor of national, naval, and maritime strategy and director of the Institute for Future Warfare Studies at the Center for Naval Warfare Studies, U.S. Naval War College. He is the author of  Anti-Access Warfare: Countering A2/AD Strategies  (Naval Institute Press, 2013) and two earlier books on the future security environment. He is a frequent contributor to  Proceedings Today  and  Proceedings , most recently, co-author of “Amphibs in Power Projection and Sea Control” ( Proceedings , April 2018).



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