Summary:
Vietnam has sharply increased its construction and military fortification efforts across the Spratly Islands, reclaiming over 534 acres in the past year and expanding infrastructure at 27 sites on at least 18 reefs, according to satellite analysis published by Radio Free Asia in June 2026. This surge, which includes a major new runway at Barque Canada Reef and significant upgrades at multiple other features, is part of Hanoi’s strategy to deter Chinese interference with its maritime economic activities and reinforce its sovereignty claims. Despite these efforts, Vietnam’s capabilities remain outmatched by China, which has established expansive military bases on seven major Spratly features. Other claimants—namely the Philippines, Malaysia, and Brunei—maintain more limited presences, with varying degrees of infrastructure and diplomatic engagement. The ongoing militarization of the Spratlys has heightened regional tensions, with the islands’ strategic value rooted in their role as forward military bases, surveillance outposts, and platforms for asserting control over vital maritime resources.
Detailed Report
1. Vietnam’s Construction and Military Build-up: Scale, Locations, and Objectives
Vietnam has embarked on its most ambitious campaign of land reclamation and infrastructure development in the Spratly Islands to date. According to a June 2026 report by Radio Free Asia, satellite imagery reveals active construction at 27 sites across at least 18 reefs, with 534 acres reclaimed in the past year and a cumulative total exceeding 2,800 acres since 2021, as corroborated by the Asia Maritime Transparency Initiative. Key developments include a new 13,000-foot runway and navigation beacon at Barque Canada Reef, major logistics and port expansions at West Reef, and significant upgrades at Spratly Island (Trường Sa Lớn), Namyit Island, Sin Cowe Island, and Sand Cay. Infrastructure types range from airstrips and helipads to hardened barracks, ammunition depots, radar and communications arrays, navigation beacons, seawalls, desalination plants, and solar power arrays. According to AMTI, these efforts are intended to deter Chinese action against Vietnamese economic activity at sea, including fishing and offshore oil and gas. Despite the scale of these efforts, Vietnam’s military capabilities in the Spratlys remain significantly outmatched by China’s more advanced and expansive installations.
2. China’s Dominant Military Presence and Strategy
China remains the preeminent power in the Spratly Islands, having transformed seven features—Fiery Cross Reef, Subi Reef, Mischief Reef, Gaven Reef, Hughes Reef, Johnson South Reef, and Cuarteron Reef—into major military outposts since 2013. According to the Council on Foreign Relations and AMTI, China has reclaimed over 3,200 acres, far surpassing any other claimant. These bases are equipped with four operational airstrips (with a fifth reportedly under development), HQ-9 surface-to-air missile batteries, YJ-12 anti-ship cruise missiles, comprehensive radar and electronic warfare systems, and large ports capable of hosting naval vessels. China’s coastguard and maritime militia fleets are routinely deployed for “gray-zone” operations, including harassment of Vietnamese and Philippine vessels. Beijing’s “salami-slicing” approach—the strategy of using small, incremental actions to achieve a major goal, as characterized by the Congressional Research Service—has shifted the regional balance of power through measures such as island construction, maritime militia deployments, and gradual administrative expansion, each individually too limited to provoke a decisive response but cumulatively reshaping effective control over disputed waters. Central to China’s strategy is its “nine-dash line” claim—a U-shaped demarcation line on Chinese maps that encompasses nearly 90% of the South China Sea and which Beijing uses to assert historic rights over waters also claimed by Vietnam, the Philippines, Malaysia, Brunei, and Indonesia. The 2016 Permanent Court of Arbitration ruled that the nine-dash line has no legal basis under the United Nations Convention on the Law of the Sea, but China has rejected the decision as “null and void” and continued its activities, including recent construction at Antelope Reef and water cannon attacks on Philippine vessels.
3. The Philippines: Fortification and Alliance-Building
The Philippines occupies nine features in the Spratlys, with Thitu Island (Pag-asa) serving as the administrative center of the Kalayaan Island Group. A persistent flashpoint is the BRP Sierra Madre at Second Thomas Shoal—a World War II-era tank landing ship that the Philippines deliberately ran aground on the shoal in 1999 to serve as a permanent military outpost, to physically assert Manila’s sovereignty over the feature, which lies within its exclusive economic zone. The vessel has been the site of repeated incidents involving Chinese water cannon and ramming attacks in 2024 and 2025, as Chinese coast guard and maritime militia vessels routinely attempt to block or harass Philippine resupply missions to the Marines stationed aboard. Philippine construction efforts have focused on runway repairs, new barracks, a desalination plant, and civilian infrastructure on Thitu Island. The Philippines has strengthened its defense posture through the Enhanced Defense Cooperation Agreement with the United States, granting access to nine bases, including Balabac Island, and has deepened security ties with Vietnam through a bilateral defense pact signed in August 2024. Joint exercises with the US, Japan, Australia, and France further underscore Manila’s alliance-building strategy.
4. Malaysia: Incremental Upgrades and Diplomatic Restraint
Malaysia maintains a lower profile, occupying five features with its primary outpost at Swallow Reef (Layang-Layang/Pulau Layang-Layang). The site hosts an airstrip, a small naval base, and resort facilities. Malaysia has undertaken incremental upgrades to its airstrip and radar/communications systems but has avoided large-scale reclamation or militarization. Kuala Lumpur has called for a stronger ASEAN response to Chinese activities, aligning with the Philippines and Vietnam, but continues to prioritize diplomatic engagement and regional stability.
5. Brunei: Diplomatic Engagement Without Physical Presence
Brunei claims a sector of the Spratlys centered on Louisa Reef but maintains no physical presence or military outposts. Its approach is purely diplomatic, advocating for peaceful resolution of disputes under the United Nations Convention on the Law of the Sea. Brunei established an exclusive fishing zone in 1984 but has not constructed any infrastructure in the archipelago.
6. Strategic Significance
The Spratly Islands’ strategic value lies in their function as forward military bases and surveillance outposts, enabling extended air and naval reach across the southern South China Sea. Control of these features allows for enhanced monitoring of maritime activity and supports Anti-Access/Area Denial (A2AD) strategies, particularly through China’s deployment of missile batteries, radar systems, and airfields. Vietnam’s fortified outposts serve as potential tripwires, raising the costs of any forced seizure. The archipelago is also believed to contain significant oil and gas reserves and supports rich fishing grounds, intensifying the competition for control. The legal framework remains contested: the 2016 Permanent Court of Arbitration ruling clarified that most Spratly features are rocks or low-tide elevations not entitled to exclusive economic zones, but China’s rejection of the ruling has perpetuated a legal vacuum, encouraging “facts on the ground” strategies by all claimants.
Conclusion
Vietnam’s accelerated construction and military build-up in the Spratly Islands reflect its determination to bolster sovereignty claims and safeguard maritime interests, yet remains overshadowed by China’s far more extensive and advanced military presence. Other claimants, including the Philippines, Malaysia, and Brunei, maintain more limited roles, relying on a mix of infrastructure, alliances, and diplomacy. The strategic significance of the Spratlys is rooted in their utility as platforms for force projection, surveillance, and resource control, with ongoing militarization raising the risk of confrontation and underscoring the complexity of managing stability in the South China Sea.