Vietnam has significantly expanded its island-building efforts across the Spratly Islands in the South China Sea. According to a report released on Friday (Aug 22) by the Washington-based Centre for Strategic and International Studies (CSIS), recent satellite imagery shows Hanoi’s unprecedented reclamation drive is now poised to match—and potentially surpass—the scale of China’s notorious island-building campaign over the past decade.
The CSIS Asia Maritime Transparency Initiative (AMTI) revealed that since early 2025, Vietnam has conducted dredging and landfill work on eight additional features, extending reclamation to all 21 of the maritime outposts it occupies in the Spratlys. What once were isolated pillbox structures perched on rocks or submerged reefs have now been transformed into sprawling artificial islands—complete with fortified infrastructure, storage facilities, and in some cases, the foundations for airstrips.
This expansion marks a turning point in Southeast Asia’s maritime contest. For years, Vietnam had been one of several smaller claimants trying to resist Beijing’s sweeping territorial assertions in the South China Sea. Now, with the scale of its reclamation nearly equaling China’s, Hanoi is sending a signal: it intends not only to defend its claims but to consolidate them physically, militarily, and symbolically.
The South China Sea is one of the world’s busiest waterways. Roughly $3 trillion in trade passes through its sea lanes annually, and beneath its waters lie potentially vast reserves of oil, natural gas, and fisheries critical to the food security of hundreds of millions. Control of the sea—and especially of the Spratly and Paracel Islands—offers not only economic leverage but also strategic dominance in maritime Asia.
China claims nearly the entire sea under its so-called “nine-dash line”, overlapping with the exclusive economic zones (EEZs) of Brunei, Malaysia, the Philippines, and Vietnam. Since 2013, Beijing has built more than 3,200 acres of artificial islands in the Spratlys, equipping them with runways, radar stations, and anti-air and anti-ship missile systems.
The United States and its allies have consistently opposed China’s activities, citing the 2016 ruling by the Permanent Court of Arbitration in The Hague, which invalidated Beijing’s sweeping claims under international law. Yet despite diplomatic pushback and freedom of navigation operations (FONOPs) by U.S. naval vessels, China’s fortified outposts remain firmly entrenched.
Until recently, Vietnam’s own reclamation efforts were modest by comparison. While it maintained garrisons on more than 20 reefs and islands, most featured little more than small barracks, watchtowers, and communication stations. That began to change in 2021 with the first round of dredging, but the full scope of Hanoi’s ambitions is only now becoming clear.
According to CSIS, Vietnam has in 2025 alone extended reclamation to Alison Reef, Collins Reef, East Reef, Landsdowne Reef, and Petley Reefs—locations that previously hosted only minimal structures. New expansion has also begun at Amboyna Cay, Grierson Reef, and West Reef, where medium-sized artificial islands already existed.
The cumulative effect is sweeping. As of March 2025, Vietnam had created about 70 percent as much artificial land as China had in the Spratlys. With new dredging underway at eight additional sites, analysts project that Vietnam could soon surpass China’s reclamation totals—a development few would have predicted even five years ago.
“Vietnam has now transformed all 21 of its occupied features into artificial islands,” the CSIS report noted. “Where once there were small fortified outposts, there are now expansive landmasses capable of hosting logistics hubs, storage depots, and potentially, air operations.”
This transformation has taken place quietly but steadily. Unlike China, which often publicized its island-building as part of a broader narrative of “sovereignty restoration,” Hanoi has pursued its reclamation largely out of the international spotlight. Only now, with satellite imagery documenting the scale, has the full scope of the expansion been revealed.
Perhaps the most consequential element of Vietnam’s expansion is its clear military dimension. The CSIS report highlighted the appearance of munitions storage containers and depots on several reefs, including Barque Canada Reef, Discovery Great Reef, Ladd Reef, Namyit Island, Pearson Reef, Sand Cay, and Tennent Reef.
The positioning of these facilities suggests that Hanoi is preparing to stockpile weapons and ammunition across its Spratly outposts, allowing for dispersed logistics in the event of a conflict. Unlike China, which has built multiple runways capable of supporting heavy bombers and fighter jets, Vietnam appears more focused on creating a network of fortified, mutually reinforcing outposts.
One significant development is the apparent construction of a runway at Barque Canada Reef, which would complement Vietnam’s existing airstrip at Spratly Island. While analysts believe space constraints preclude full-length runways at most features, the addition of even one more functional airbase could greatly enhance Vietnam’s ability to rotate aircraft through the Spratlys, extending surveillance and patrol coverage deep into contested waters.
“Vietnam is not attempting to replicate China’s fortress islands one-for-one,” explained Gregory Poling, director of AMTI. “Instead, they are pursuing an asymmetric strategy: smaller, hardened, dispersed facilities that complicate China’s military calculus.”
In military doctrine, such a strategy is known as “area denial”—the ability to deter or slow an adversary’s operations without necessarily establishing outright dominance. By hardening its island outposts, Vietnam could make any attempt by China to seize them costly, buying time for reinforcements or international diplomatic pressure to mount.
Predictably, Beijing has denounced Vietnam’s activities. In February 2025, the Chinese Foreign Ministry specifically condemned construction at Barque Canada Reef, asserting that the feature was “indisputably Chinese territory.”
China’s embassy in Washington did not respond to requests for comment on the latest CSIS report. Historically, however, Beijing has framed all rival construction in the South China Sea as illegitimate, even as it continues to fortify its own artificial islands.
“The irony is striking,” said Carlyle Thayer, a longtime Vietnam analyst and emeritus professor at the University of New South Wales. “China has engaged in the largest land reclamation campaign in modern history, yet it objects vociferously when Vietnam attempts to safeguard its own claims.”
Vietnam, for its part, has consistently argued that its activities are defensive in nature and confined to features it has occupied for decades. By international law, Hanoi insists, its actions are fully within its rights.
Vietnam’s surge in island-building carries implications well beyond its bilateral rivalry with China. Other South China Sea claimants—particularly the Philippines and Malaysia—will be watching closely.
Manila, which has clashed repeatedly with Chinese vessels at Second Thomas Shoal and other contested areas, has begun modest construction of its own in the Spratlys. Yet it lacks Vietnam’s combination of engineering capability, political will, and military readiness.
Some analysts warn that Hanoi’s assertiveness could trigger a “regional reclamation race,” with smaller states attempting to expand their presence before China consolidates control completely. Others argue that Vietnam’s moves may actually strengthen regional deterrence by showing that China does not have a free hand in shaping the South China Sea.
The United States and its allies, meanwhile, may view Vietnam’s reclamation as both a challenge and an opportunity. On one hand, Washington has consistently criticized island-building—whether by China or others—as destabilizing. On the other, a more militarily capable Vietnam could serve as a counterweight to Beijing, reinforcing the U.S. strategy of supporting a “free and open Indo-Pacific.”
For Vietnam, the decision to escalate reclamation carries significant risks. China’s economic and military power dwarfs that of Hanoi, and Beijing could choose to retaliate economically—Vietnam is heavily dependent on trade with its northern neighbor—or militarily, through intensified pressure at sea.
Yet Vietnam has long pursued what scholars call a policy of “cooperating and struggling” with China: engaging in trade and diplomacy while quietly building its defensive capabilities. Island reclamation appears to be the latest expression of this strategy.
“Vietnam cannot match China plane for plane or ship for ship,” said Nguyen The Phuong, a defense analyst in Ho Chi Minh City. “But it can make sure that if conflict comes, China pays a heavy price for any attempt to dislodge Vietnamese forces from the Spratlys.”
This approach fits within Vietnam’s broader national defense posture, which emphasizes “people’s war” at sea: distributed resistance, leveraging geography, and maximizing the costs of aggression.
The legality of Vietnam’s reclamation is also under scrutiny. While China’s nine-dash line claim was dismissed in the 2016 arbitration ruling, the tribunal did not explicitly resolve sovereignty over individual features.
Hanoi argues that its control of the reefs and islands it occupies predates China’s large-scale reclamation campaign, and that fortifying them merely preserves the status quo. Critics, however, caution that any artificial expansion—even by Vietnam—complicates efforts to manage disputes under international law.
The Hague ruling remains a touchstone in the debate. For Southeast Asian states, it offered a rare legal victory against Beijing. Yet without enforcement, its impact has been limited. Vietnam’s reclamation may thus reflect a sobering recognition: in the South China Sea, physical control often trumps legal arguments.
The trajectory of Vietnam’s island-building suggests that the contest for the South China Sea is entering a new phase. Several scenarios are possible in the months ahead:
- Escalating Militarization – As Vietnam completes dredging and fortifies its new islands, China could respond with increased naval patrols, maritime militia swarms, or even its own new construction to maintain dominance.
- Diplomatic Pushback – ASEAN or external powers could call for a moratorium on new reclamation, though enforcement remains doubtful. Vietnam may seek to frame its actions as defensive and consistent with international law.
- Strategic Balance – Vietnam’s new islands could create a more even playing field, reducing China’s ability to coerce its neighbors unilaterally. This could either stabilize the region or raise the stakes for any future confrontation.
Ultimately, the outcome will hinge not only on Vietnam and China but also on the reactions of the United States, ASEAN partners, and the wider international community.
