A recent article in the South China Morning Post caught my eye—the topic being why Beijing has taken such an apparently different approach to its territorial disputes with Vietnam versus the similar disputes it has with the Philippines.

Given the now weekly near misses between competing claimants in the South China Sea, the topic is a timely one, and in analyzing Beijing’s contrasting responses to territorial claims by Vietnam and the Philippines in the South China Sea, it becomes clear that China’s strategic calculations are shaped by varying historical, political, and diplomatic dynamics.

Historically, Vietnam’s claims to the South China Sea date back several centuries, although the exact extent and nature of these claims have evolved significantly over time.

Vietnamese records from the Nguyễn Dynasty (1802–1945) suggest that Vietnamese rulers asserted control over certain islands and features in the South China Sea. And references to the Spratly and Paracel Islands appear in historical texts from as early as the seventeenth century. These documents suggest that Vietnamese fishing fleets and merchant vessels regularly visited the islands and considered them within their traditional maritime territory.

When France colonized Vietnam in the late nineteenth century, it began asserting territorial claims on behalf of the Vietnamese protectorate in the South China Sea. In the 1930s, the French government formally claimed both the Paracel and Spratly Islands, citing historical Vietnamese sovereignty. The French established outposts and conducted surveys on some of the islands, mainly driven by the strategic importance of the South China Sea for naval dominance. These colonial claims are crucial because they form part of the modern Vietnamese argument that sovereignty was maintained through continuous occupation, even when the country was under colonial rule.

After the French withdrew in 1954, both North and South Vietnam laid claims to the islands, though South Vietnam maintained physical control over most of the features in the South China Sea. Following the Vietnam War and the reunification of Vietnam in 1975, the unified Socialist Republic of Vietnam continued asserting sovereignty over the islands and expanded its presence in the Spratlys, bolstering its post-colonial efforts to keep the islands under effective control through patrols and the construction of outposts even as China began moving to assert its claims.

The longstanding control of these features is one reason why Beijing has been relatively restrained in responding to Hanoi’s recent expansion activities.

Moreover, Vietnam’s strategy of managing maritime disputes with Beijing “quietly” contrasts sharply with the Philippines’ approach of publicizing clashes and appealing to international forums. Vietnam’s decision to handle disputes internally and seek “friendly consultations” has helped to de-escalate tensions with China, despite the fact that its island-building mirrors China’s own efforts over the past decade.

Indeed, the political relationship between China and Vietnam is arguably the key factor shaping Beijing’s measured response. As the article from the South China Morning Post notes, the overall bilateral relationship is defined by economic cooperation and mutual geopolitical interests, including China’s Belt and Road Initiative. As a result, Beijing seeks to preserve its broader relationship with Vietnam, using diplomacy and economic enticements as buffers against outright hostility. This is in contrast to the Philippines, whose defense ties with Washington have escalated tensions. The longstanding U.S.-Philippine alliance is viewed by Beijing as part of a broader strategy of “containment,” especially in light of the recently revived Enhanced Defense Cooperation Agreement, which gives the U.S. military access to more bases close to Taiwan and the South China Sea.

The Philippines has made headlines by consistently publicizing its maritime disputes with China. Videos of Chinese coast guard vessels colliding with Philippine boats and the use of water cannons have garnered international attention, forcing Beijing to defend its actions diplomatically. Furthermore, Manila’s close alignment with Washington, particularly under President Ferdinand Marcos Jr., has heightened tensions with China. This is exacerbated by joint military exercises between the Philippines, the United States, and other allies like Japan and Australia. For Beijing, this has elevated the Philippines to a higher priority in terms of countering what it perceives (correctly) as a U.S.-led containment effort in the region. Vietnam, by contrast, has avoided such provocative military cooperation with external powers, further explaining why Beijing’s approach has been comparatively restrained.

The American role in the region cannot be understated. Washington’s decision to interpret existing treaty obligations to defend Manila in the event of an armed attack under the U.S.-Philippine Mutual Defense Treaty raises the stakes significantly and decreases the likelihood that Manila will choose to deescalate. This brings into focus the risk of conflict between the United States and China in defense of territorial claims in the South China Sea, which would likely start with a confrontation over the Scarborough Shoal or Spratly Islands. Beijing has increasingly seen its conflict with Manila as an extension of the U.S.-China strategic rivalry, particularly regarding Taiwan, which further complicates the maritime disputes and endangers the world.

At the same time, as Beijing seeks to prevent a collective response from claimant states, recognizing that pushing too hard against Vietnam could drive Hanoi closer to the United States and its allies. While Vietnam has taken advantage of Beijing’s focus on the Philippines to accelerate its island-building activities, Beijing’s restraint towards Vietnam does not rule out future escalations, especially if Vietnam’s militarization of these features intensifies.

While much is uncertain, one thing seems clear: far from being a force for peace in the region, Washington’s intervention, far from America’s own shores, is a clear source of instability and potential danger.