China’s ambition: South China Sea
“The throat of international commerce … demographic cockpit of the globe.”
Robert Kaplan
Introduction
While watching events unfold in the US-Iran War, I noted a July 15, 2026 report that the US Coast Guard (USCG) was redeploying six Sentinel-class fast response cutters from Bahrain to the Western Pacific, specifically to Singapore and the Philippines.
I should say “had deployed” because I believe they had already left the Persian Gulf before the US war with Iran began in February 2026.
The USCG has had six cutters in Bahrain for the past 20 years, under the command of the US 5th Fleet. It was named Patrol Forces Southwest Asia.
The USCG has reorganized these cutters into the Expeditionary Cutter Squadron, available to combatant commanders worldwide as needed. They will now be available to the Pacific Command (PACOM) until at least September 30, 2026. Plans beyond that have not been released.
The cutters involved are the Charles Moulthrope, Robert Goldman, Glen Harris, Emlen Tunnell, John Scheuerman, and Clarence Sutphin Jr. USNI News reported that the cutters were seen in Singapore in late March 2026, supporting my belief that they left Bahrain before the US-Iran War began.
These cutters can exceed 28 knots, have a range of 2,500 miles, and can endure heavy seas. They can remain at sea for five days. They are armed with a 25-mm machine gun and four crew-served .50-caliber machine guns.
To demonstrate their versatility, two of the cutters, the Moulthrope and Tunnell, were operating within the Philippine Exclusive Economic Zone (EEZ) in late June and participated in a combined exercise on July 15 in the Gulf of Thailand. They then proceeded to the Philippines.
In July 2026, a USCG spokesperson said that the cutters will rotate between Singapore and Subic Bay, a former USN base overlooking the SCS.
One might say the US needed to get the cutters out of the Persian Gulf before the war with Iran began. I accept that, but I would say it was a blessing in disguise.
China’s growing presence in the South China Sea (SCS) underlies this USCG redeployment and recasting. The cutters were needed in the Western Pacific to maintain the balance of power between China and the US in the SCS.
Chinese expansion in the SCS has posed a problem for China’s southern neighbors and now challenges the US protective cover for those nations.
Robert Kaplan, in his book Asia’s Cauldron: The South China Sea and the End of a Stable Pacific, explains the importance of this American protective cover in riveting detail, far more than I can cover here, though I will refer to his work.
CSIS Island Tracker
The Center for Strategic and International Studies (CSIS) has created the Asia Maritime Initiative (AMTI) to “promote transparency in the Indo-Pacific to dissuade assertive behavior and conflict.” One output of the AMTI is “Island Tracker,” in which CSIS analysts present satellite imagery of islands and reefs in the South China Sea (SCS) that China claims.
I recommend that you browse the Island Tracker photos. They will open your eyes to the breadth of Chinese activity in the SCS. This imaghe is an example of what the Chinese have done to Fiery Cross Reef in the Spratly Islands.
Four other countries have claims in the SCS and have built facilities on some of the islands and reefs which you can observe on the Island Tracker: Vietnam, the Philippines, Malaysia, and Taiwan. Indonesia has not made any claims, but China’s overall claim overlaps Indonesia’s Exclusive Economic Zone (EEZ) around the Natuna Islands. Indonesia therefore opposes Chinese expansion.
None of these countries can force the Chinese to abandon their claims.
The US sending six fast-response Coast Guard cutters to the region is an appropriate, possibly even a brilliant, response.
To use a Coast Guard saying, “Meet presence with presence.”
It is one thing for Chinese coast guard or naval ships to fire water cannons at Filipino fishermen or coast guard vessels and even ram them. It’s quite another to do so against USCG cutters.
The idea is to maintain a balance of power in the SCS region and prevent China from becoming the dominant power there.
What is so special about the SCS?
Kaplan calls the SCS “the demographic cockpit of the globe.” He also notes that “Europe is a landscape. East Asia is a seascape.” That’s an important comparison. Let’s see why he says that.
One estimate says $2.4 trillion in goods passed through the Strait of Malacca and the Strait of Taiwan in 2024, and overall $6.4 trillion in goods passed through the SCS in 2024.
The CSIS research house has identified eight straits that are chokepoints for seaborne traffic in the SCS: Taiwan, Luzon, Mindoro, Balabec, Makassar, Lomboc, Sunda, and Malacca.
Rystad Energy has estimated that there are 3.6 billion barrels of petroleum and other liquids and 40.3 trillion cubic feet of natural gas in the SCS region. Most discovered oil and gas has been found near the shorelines of six countries bordering the SCS. The rest is out at sea and underneath the sea.
China imports 11.1 million barrels per day of crude oil, about 74 percent of its consumption. Most of this oil comes from Russia, Saudi Arabia, Malaysia, Iraq, and Oman. It is estimated that 90 percent of China’s oil arrives by sea.
The point is that China is concerned about the security of its oil supplies.
Another central point stands out. The US does not rely on seaborne traffic through the SCS. But those smaller nations surrounding the SCS do rely on a strong US naval and air presence. They are cautious about dealing with the US, but they rely on it nonetheless.
Naval power is what counts in this region of the world. China’s sea and air power are growing, enough to position it to tilt and upset the global balance of power. This is a challenge to the US 7th Fleet which has plied these seas for many decades.
Jihyun Kim has wondered whether China’s expansionism in the SCS “might trigger major power realignments” globally. On the other hand, she refers to Joseph Nye’s “counsel that ‘the best way to make an enemy of China is to treat it like one,’ leading to a self-fulfilling prophecy.”
Chinese “Nine-dash Line”
In 2009, China submitted its Notes Verbales to the United Nations (UN) and attached the “nine-dash line” map, thereby placing Chinese claims in the UN’s official record and surprising much of the world. The Chinese were serious. These notes claimed that,
“China has indisputable sovereignty over the islands of the South China Sea and the adjacent waters, and enjoys sovereign rights and jurisdiction over the relevant waters as well as the seabed and subsoil.”
The term “nine-dash” refers to a post-WWII map that shows nine dashes in a U-shape over the SCS, sometimes called the “Cow’s Tongue.” These dashes on the map enclose China’s claim to the SCS, meaning the entire SCS.
Robert Kaplan calls the SCS “the throat of international commerce where most of the hydrocarbon shipments, most of the merchant trade, the container ships, all come together,” a kind of “Asian Mediterranean.”
The thrust of China’s claims has focused on the Paracel and Spratly Islands. Recently, it has added the Scarborough Shoal. I’ll address this addition shortly. China uses historical analyses to underscore its claims.
Not only did China set down these markers, but it also stated that it could decide how to use these islands, maintain a physical presence there, and install both military and non-military facilities.
China has 20 outposts in the Paracel Islands and seven in the Spratly Islands. The Spratly Islands have drawn the most attention. Vietnam claims 49 to 51 outposts across 27 features in the Spratly Islands; the Philippines, 9; Malaysia, 5; and Taiwan, 1.
Most of the bickering among the concerned nations has been handled through legal and diplomatic channels, including the UN Commission on the Limits of the Continental Shelf (CLCS). China’s claims are based on its assessment of ancient history; Vietnam’s claims are more based on its contintinental shelf, much closer to the areas claimed than China’s.
That said, military forces, including coast guard forces, have confronted one another. Chinese, Filipino, and Vietnamese naval and coast guard forces have clashed in the Spratly and Paracel Islands. Some conflicts have resulted in the loss of lives and ships.
In 2016, the Permanent Court of Arbitration at the Hague confirmed that China’s claim to historic rights to resources in the South China Sea was “incompatible with the exclusive economic zones” and that “there was no evidence that China had historically exercised exclusive control over the waters or their resources.”
China rejected and dismissed the decision. The US position, shared by its allies, has been that freedom of navigation and overflight should be maintained throughout the SCS. The US views China’s plans as destabilizing.
On July 13, 2020, Secretary of State Mike Pompeo issued a press statement that said,
“Beijing’s claims to offshore resources across most of the South China Sea are completely unlawful, as is its campaign of bullying to control them.”
Secretary of State Marco Rubio recently called Chinese expansionism in the SCS “disturbing.”
Rubio highlighted the core of US policy on the SCS islands and the claims: The US will maintain its presence in East Asia and is committed to freedom of navigation.
The US National Security Strategy of 2025 underscores this policy: maintain the deterrence needed to keep the sea lanes open and free.
The US National Defense Strategy of 2026 states that the US must prevent China from dominating the US or its allies.
Scarborough Shoal
Special concern has been expressed about China’s claim to Scarborough Shoal, about 120 miles due west of Luzon, the Philippines, and within the Philippines Exclusive Economic Zone (EEZ). China asserts sovereignty over the shoal.
Two Chinese scholars, Zhihua Zheng and Jiawei Wang, have said that Chinese military planners have linked the Paracel Islands to the north, the Spratly Islands to the south, and the Scarborough Shoal to the northeast, forming what they call an “Iron Triangle,” through which 40 percent of the world’s international trade and transportation by sea and 60 percent of global gas and oil must pass.
This has caught my attention.
On September 10, 2025, China announced plans to establish a nature preserve on Scarborough Shoal, which is currently the weakest point of the triangle. It remains an open question whether China will build a military base there.
Scarborough Shoal, called Huangyan Dao by the Chinese, is about 500 miles from China and beyond its continental shelf.
Nonetheless, China claims it has “indisputable sovereignty” over the shoal. China uses historical analyses to underscore its claims. Scarborough Shoal is part of the Zhongsha Islands in the SCS. All islands except the Scarborough Shoal are underwater. The Shoal is barely above water.
International reactions
The CIA reported in August 1988 that Chinese naval operations in the SCS and the construction of bases in the Spratly Islands were part of a long-term strategy to assert sovereignty. The Chinese navy has demonstrated the ability to project power and has been doing exactly that.
I was surprised at the international reactions to these matters.
Early on, in 1991, the commander of the Pacific Command, Admiral Charles Larson, said that “there was no interest for the US to intervene,” calling the Chinese actions a “regional issue.” The Association of Southeast Asian Nations (ASEAN) also did not want to get involved.
However, given the breadth of Chinese expansion in the SCS, the tide has started to turn.
President Obama drew attention to the problem. Interest grew even more in 2009, when five Chinese trawlers surrounded the USNS Impeccable and approached dangerously close. The trawlers even tried to snag an acoustic sonar array with grapple hooks. The Impeccable, a surveillance ship, was operating off the coast of Hainan Island, China.
In 2010, Secretary of State Hillary Clinton said the region “was pivotal to US national interests.” In 2012, a Filipino naval ship remained near the Scarborough Shoal for a few days, and China sent a heavily armed patrol ship to the area. A typhoon arrived, and the two sides withdrew.
By 2013, the Chinese had become more aggressive in land reclamation and militarization. In 2014, Vietnam and China came to blows at sea after China established an oil rig 130 miles off Vietnam’s coast. Chinese ships fired water cannons at a Vietnamese ship, injuring six Vietnamese.
Then, in 2015, Secretary of Defense Ashton Carter raised the ante, calling the Chinese islands “massive outposts” and warning against their militarization. In late 2015, the US and the Philippines signed an Enhanced Defense Cooperation Agreement. USN ships were deployed to Subic Bay, which had been closed since 1992. The US began sea and air patrols of the SCS.
All that said, no one other than the Chinese and Vietnamese seems willing to “make a federal case” out of the problem, though the recent USCG cutter deployment might change that.
In his book, Robert Kaplan devotes considerable time to discussing Vietnam and its rivalry with China. His discussions are riveting. On the one hand, Vietnam must remain close to China because China, a major power, borders it and because Vietnam must trade with China for economic reasons. However, Kaplan argues that Vietnam is more “Indo” than Chinese; there is a difference, one that explains why France called Vietnam, Laos, and Cambodia Indochina.
Jacopo Romanelli, writing for The Vietnamese, has written,
“One of the most significant yet underappreciated developments today is Việt Nam’s gradual transition from a primarily coastal defender to a forward-operating maritime power in the Spratly Islands.
“Việt Nam’s expanded construction activity in the Spratly Islands is at the center of this transformation. According to (Gregory) Poling, the country has moved well beyond the symbolic occupation of maritime features and is now systematically developing infrastructure to support sustained operational deployment.”
Filipino President Rodrigo Duterte (2016-2022) backed away from dependence on the US for protection and instead sought to get closer to China. For his part, President Donald Trump sought greater engagement with China. The net effect was that the SCS no longer had center stage. ASEAN has largely stood on the sidelines.
It is difficult to anticipate the next shoe to drop. The Chinese are intent on building their stakes in the SCS, and the other countries are jealously guarding theirs.
Falling back to Jacopo Romanelli, that “this dual dynamic–Việt Nam expanding in the Spratlys while China strengthens its positions in the Paracels, creates a geographically dispersed but increasingly interconnected pattern of competition.”
Romanelli continues,
“Rather than a single focal point of tension, the South China Sea is becoming a lattice of overlapping zones where both sides are increasing their ability to monitor, intercept, and respond to each other’s activities.
“This structure does not necessarily lead to an immediate escalation of the crisis, but it significantly increases the frequency of contact between opposing maritime forces.”
This is where I see the six USCG cutters coming into play. The Philippines lies within the First Island Chain, which includes the Kurile Islands, the Japanese archipelago, and Taiwan, extending to Borneo. This line forms a containment line for the US, beyond which it does not want China to reach.
Chinese actions at the Scarborough Shoal come perilously close to this containment line. The southern part of the First Island Chain faces the Chinese Nine-Dash Line.
The US considers the First Island Chain a defensive barrier, and it relies on regional allies to manage its security, including Australia. The end result has been the evolution of yet another point of strategic competition between the US and China, one the US attempted to avoid in earlier years.
Note, however, that the regional allies want a significant US naval and air presence, but they are not willing to go too far out on a limb with the US. The arrangements are delicate but important.
The Association of Southeast Asian Nations (ASEAN) held its 2026 conference in Manila from July 19 to 24. Brunei, Cambodia, Indonesia, Laos, Malaysia, Myanmar, the Philippines, Singapore, Thailand, Timor-Leste, and Vietnam are members. China is not a member because it identifies as an East Asian country rather than a Southeast Asian one.
Concomitant with that notion, Vietnam refers to the South China Sea as the East Sea; to wit, no China involved, even though China is intimately involved.
Nonetheless, two days after the conference closed, on July 26, 2026, the China Coast Guard (CCG) used water cannons to drive away two Philippine vessels that China says “intruded into waters off China’s Huangyan Dao (Scarborough Shoal).”
The Chinese have militarized the Paracel and Spratly Islands. CSIS AMTI draws readers’ attention to four islands in the SCS that China claims and that host 10,000-ft. runways: Woody Island, Fiery Cross Reef, Mischief Reef, and Subi Reef. Take a look for yourselves at “Island Tracker.”
Theoretically, Chinese fighter aircraft can use these runways to cover all of Taiwan, the Philippines, Borneo, the Malay Peninsula, and Southeast Asia. However, in combat, these fighters’ range is reduced to cover only the SCS between the Philippines and Vietnam.
Robert Kaplan has suggested the US will not go to war with China over the SCS, a Mutual Defense Treaty with the Philippines notwithstanding. He feels China wants to “dilute American naval presence.”
Jihyun Kim seems to agree, asserting that China is challenging US primacy and the US capacity and willingness to protect its allies in the region.
I’ll leave you with this last, sobering thought. Robert Kaplan has said, in an interview,
“Keep in mind that without American naval and air power, the
chances of a war between China and Japan go up dramatically.”
I’ll have to think about that. They both starve for oil, and many historians have suggested that Japan went to war with the US in the 1940s because the US was inhibiting it from getting greater oil access.
