ESSAY: ASEAN uses the Hormuz crisis to accelerate the South China Sea Code of Conduct

Introduction: When a crisis serves as a diplomatic lever

The logic of constructive shock

History holds crises that, instead of paralyzing, catalyze. The Strait of Hormuz crisis of March to June 2026 belongs in that category — at least in its Indo-Pacific dimension. While the world watched the partial paralysis of global oil trade, a discreet but significant movement was unfolding within ASEAN: the Philippines used the demonstration offered by Hormuz to push their partners to accelerate negotiations for a Code of Conduct in the South China Sea.

The argument is simple, almost brutal in its logic: the closure of a strategic strait paralyzes the world economy. Hormuz proved it. The South China Sea is a vital corridor for an even greater share of world trade — 40% of global maritime traffic transits there by most estimates. If that corridor were to become the subject of a similar crisis, the economic consequences would be of even greater magnitude.

ASEAN facing an uncomfortable arithmetic

ASEAN brings together 10 members, of which 4 have territorial claims in the South China Sea — Brunei, Malaysia, the Philippines, and Vietnam. These members are also China's major trading partners. The balance between defending their sovereign interests and maintaining economic relations with Beijing is a structural tension that complicates any collective ASEAN position toward China.

This is the tension the Philippines are seeking to resolve through the Hormuz comparison. The Philippine argument is subtle: it is not solely about sovereign rights — it is about collective economic risks. Instability in the South China Sea threatens all ASEAN members, including those who prefer to avoid a confrontation with Beijing. Common economic interest thus becomes the terrain for a difficult but possible consensus.

The Hormuz crisis as a pedagogical demonstration

Hormuz — proof that straits can be closed

The Strait of Hormuz connects the Persian Gulf to the Sea of Oman. Approximately 20 to 21% of global oil trade transits it. Its disruption between March and June 2026 created a worldwide economic shockwave — oil price spikes, logistical disruptions, industrial slowdowns in importing countries. The lesson is unforgettable: a strait can be closed, even partially, and the consequences are systemic.

The South China Sea is not a strait — it is a semi-enclosed sea with several strategic passages. But the logic applies: if China were to impose control strong enough to disrupt trade, the economic consequences for economies dependent on these routes would be considerable. Japan, South Korea, and Taiwan import massive amounts of energy and raw materials that transit through these waters. Their vulnerability is documented.

The Philippines explicitly using this analogy

The Straits Times of June 24, 2026 explicitly documents that the Philippines are using the Hormuz crisis to justify the urgency of a South China Sea Code of Conduct. The Philippine formulation is skillful: it is not an alarmist comparison, it is an empirical demonstration of risk. ASEAN partners can see concretely what the disruption of a strategic commercial strait means.

This Philippine argumentation is addressed particularly to ASEAN members that maintain close economic relations with China and are reluctant to support too firm a position. It tells them: regardless of your ties with Beijing, instability in the South China Sea directly affects you. The economic calculation must take precedence over geopolitical affinities.

The four claimants in the South China Sea

Brunei, Malaysia, Philippines, Vietnam — a fragmented front

The four ASEAN members with South China Sea claims — Brunei, Malaysia, the Philippines, and Vietnam — do not have a unified position. Brunei is discreet and prefers silent negotiation. Malaysia pragmatically balances its relations with China and its sovereign claims. Vietnam is perhaps the firmest in resisting Chinese pressure, having a long history of confrontation with Beijing. The Philippines under Marcos Jr. have adopted the most assertive posture.

This fragmentation is a resource for China. Beijing can negotiate bilaterally with each claimant, offering economic concessions in exchange for softer positions on territorial issues, thereby avoiding the formation of a coherent ASEAN front. This is precisely what the Code of Conduct seeks to prevent — by creating a binding multilateral framework that blocks these divide-and-rule maneuvers.

ASEAN paralyzed by consensus

The consensus rule in ASEAN is both its strength — it guarantees inclusion of all — and its main weakness — it gives each member an effective veto. China has used this rule with mastery, notably through Cambodia at the 2012 ASEAN summit in Phnom Penh, where the first communiqué-less final declaration in the organization's history revealed the deep fracture Beijing had introduced into the bloc.

Fifteen years after that embarrassing precedent, ASEAN is still trying to find a coherent position on the South China Sea. The Hormuz crisis perhaps offers an opportunity to rally the most hesitant members behind an economic argument rather than a legal-territorial one. This is a diplomatic bet the Philippines have chosen to play.

The Code of Conduct — ten years of negotiations, zero binding effect

A decade of delaying negotiations

Negotiations for a South China Sea Code of Conduct have been dragging on for more than a decade. China and ASEAN adopted in 2017 a Code of Conduct "framework" — a vague document that launched negotiations on the real content. Since then, rounds have followed rounds without ever reaching agreement on the most substantive points: the geographic scope of the Code, dispute resolution mechanisms, and above all the binding or non-binding character of provisions.

China has been consistent in its position: it accepts a Code of Conduct but refuses any binding mechanism that would deprive it of final control over interpretation. This refusal makes logical sense from Beijing's perspective — a binding Code would reduce its freedom of action in waters it considers its own. But this refusal makes the exercise largely symbolic from the claimants' perspective.

The new Philippine demands

In the current negotiations, the Philippines are demanding that the Code of Conduct include provisions on military activities in the contested zone, transparency mechanisms on construction and activities, and an explicit link to international law — notably UNCLOS and the 2016 arbitral ruling. These are precisely the provisions China refuses.

The Hormuz crisis gives the Philippines an additional argument to push these demands: the absence of clear rules creates a systemic risk that all ASEAN members endure. A Code of Conduct without transparency mechanisms and without a link to international law does not prevent crises — it manages them after the fact. And as Hormuz showed, after-the-fact management is costly for everyone.

The 2016 ruling — the ignored legal foundation

The Hague has spoken — China is not listening

In July 2016, the Hague arbitral tribunal issued a historic ruling: China's "nine-dash line" claims in the South China Sea have no foundation in international maritime law. The historical rights invoked by Beijing do not confer sovereign rights over these waters under UNCLOS. It is a clear, rigorous, and definitive ruling.

China rejected this ruling with contempt. It called it "null and void." It refused to participate in the arbitral proceedings. And it continued its expansion policy in the South China Sea as if the ruling did not exist. The Philippine Department of Foreign Affairs recalled on June 22, 2026 the validity of this ruling — a necessary reaffirmation in the face of continuing pressure.

Respect for international law as a test of global legitimacy

The fundamental question is not merely strategic — it is systemic. If a great power can impunely ignore an international arbitral ruling, the entire system of peaceful dispute resolution is weakened. The Chinese precedent tells all states: if you are powerful enough, you can disregard international law. That is an invitation to the law of the strongest that undermines the world order in all its dimensions.

The West cannot selectively support international law — invoking the UN Charter for Ukraine and ignoring the Hague ruling for the South China Sea. Consistency is the condition of credibility. Supporting the Philippines in their demand for respect of the 2016 ruling is defending a universal principle, not merely a Philippine interest.

China-Philippines tensions reach their peak in 2026

Scarborough, coast guards, harassment — gradual escalation

The year 2026 represents the highest tension point in China-Philippines relations in years. The naval confrontation of June 23 at Scarborough, the repeated blockades of Philippine coast guard vessels attempting to resupply their outposts, the harassment of fishermen — these incidents are accumulating with growing frequency and intensity.

This escalation is not the product of chance. It reflects a deliberate Chinese decision to increase pressure on Manila to test the limits of Philippine resistance and American commitment. Each incident is also a message sent to the other ASEAN claimants: this is what awaits you if you resist like the Philippines. The pressure is simultaneously specific and universal.

The collective response — a test for ASEAN

ASEAN's capacity to respond collectively to these tensions in 2026 will be a test of its institutional cohesion. If the bloc can accelerate Code of Conduct negotiations by integrating the Hormuz argument, if the most hesitant members accept supporting a firmer position, that will be a sign of collective diplomatic maturity. If the divisions persist, Beijing will have new confirmation that its divide-and-rule strategy works.

The outcome of this test depends in part on the willingness of major external powers outside ASEAN — the United States, the European Union, Japan — to concretely support members resisting Chinese pressure. American support for the Philippines is visible. European support remains insufficiently concrete. The overall equation is in fragile balance.

India in the South China Sea equation

New Delhi between interest and strategic caution

India occupies a particular position in the geopolitics of the South China Sea. It is not a direct claimant, but it has significant economic interests in the trade routes that cross these waters. Its relations with China are complex — competitive in some domains, interdependent in others, and occasionally conflictual as shown by the Galwan border crisis in 2020.

India is a member of the Quad but maintains a policy of "strategic autonomy" that leads it to avoid overly explicit alignments. New Delhi supports in principle freedom of navigation and respect for international law, but prefers not to engage directly in South China Sea disputes. This prudence is understandable given its complex relations with Beijing — but it limits the effectiveness of a common democratic front against China.

India and the strengthening of its navy

The Indian Navy is in a phase of significant expansion, with investments in aircraft carriers, submarines, and destroyers. India is developing power projection capabilities in the Indian Ocean and beyond, partly to counterbalance the growing Chinese naval presence in the Indian Ocean (the "string of pearls" doctrine). While these investments do not directly target the South China Sea, they create pressure on Chinese naval resources that must monitor multiple theaters simultaneously.

A navally strong India is a strategic factor that complicates Beijing's calculations, even if New Delhi does not explicitly engage in South China Sea disputes. Indian naval power in the Indian Ocean represents a constraint on Chinese naval movements between its bases in the South China Sea and its potential zones of influence further west. This is a form of indirect pressure that contributes to the regional balance.

Vietnam — a discreet but determined ally in resistance to Beijing

Hanoi between pragmatism and resistance

In the tableau of ASEAN facing China, Vietnam deserves special mention. Hanoi has a long history of resistance to Beijing — a history marked by wars, occupations, and tensions that predate the current period by far. This historical memory feeds a structural mistrust of China that transcends Vietnamese political cycles.

In the context of the South China Sea, Vietnam has its own claims to the Spratly and Paracel Islands — claims in direct conflict with China's. Hanoi has adopted a strategy of discreet resistance: strengthening military capabilities (Russian submarines, coastal missile systems), developing defense relations with the United States and other powers, while maintaining economic relations with Beijing to avoid triggering an open confrontation.

The Vietnam-Philippines convergence

The strategic interests of Vietnam and the Philippines in the South China Sea are largely convergent, even if their diplomatic styles differ. Hanoi is more discreet and less inclined to public confrontations with Beijing than Manila. But behind this caution, Vietnam generally supports Philippine positions in multilateral forums and shares the interest in a binding Code of Conduct that would limit Chinese actions in waters both countries claim.

This tacit convergence between the two countries is a diplomatic asset the Philippines can use to strengthen their position within ASEAN. If Vietnam and the Philippines present a common position on the key elements of the Code of Conduct — binding, linked to international law, transparent — they together represent two of the most important claimants and can exert significant pressure on more hesitant members like Malaysia and Brunei.

Conclusion: Hormuz opened a window — will we seize it?

A rare diplomatic opportunity

The Hormuz crisis created a diplomatic window of opportunity to accelerate the South China Sea Code of Conduct. The empirical demonstration of the systemic risk linked to disruptions of strategic commercial straits is a powerful argument that transcends ASEAN's habitual divisions. The Philippines seized this opportunity with intelligence and determination.

But windows of opportunity close. World attention shifts, urgencies succeed one another, and China has every interest in letting this moment pass without concluding. Pressure must be maintained — by the Philippines, by their ASEAN partners, and by external powers with a documented interest in the stability of these waters. This is a long-haul effort that cannot afford to slacken.

International law as an irreplaceable foundation

Beyond tactics and opportune moments, the foundation of any durable solution remains international maritime law — UNCLOS, the 2016 arbitral ruling, the principles of freedom of navigation. Any Code of Conduct not grounded in these foundations will be a fragile agreement that China can circumvent at will. The international community must insist that a Code of Conduct worthy of the name be anchored in international law — not in a nebulous compromise that offers Beijing the flexibility it needs to continue its strategy of gradual advance.

Signed Maxime Marquette, columnist

Columnist's transparency box

Sources and method

This essay relies on sources published between June 22 and 25, 2026: Straits Times, South China Morning Post, Manila Bulletin, Washington Times, Türkiye Today. Information on Code of Conduct negotiations, the 2016 arbitral ruling, and the Hormuz crisis comes from these sources and from basic geopolitical knowledge about ASEAN and the South China Sea.

The figure of 40% of global maritime trade transiting through the South China Sea is an estimate commonly cited in geostrategic literature. I do not have a primary source for this specific figure in the cited articles — I flag it as a commonly used reference estimate.

Editorial position

This essay supports international maritime law and binding arbitral rulings. It is critical of China's strategy in the South China Sea. It supports the efforts of the Philippines and their allies to defend their sovereign rights in accordance with international law. This position is stated openly and transparently.

I acknowledge the complexity of ASEAN members' economic interests and their trade dependence on China. My analysis acknowledges these real constraints without using them to justify accepting Chinese violations of international maritime law.

Sources

Primary sources

Straits Times — Hormuz crisis sharpens Philippines push for ASEAN Code of Conduct — June 24, 2026

South China Morning Post — China-Philippines naval confrontation at Scarborough — June 23, 2026

Secondary sources

Manila Bulletin — DFA defends the 2016 South China Sea arbitral ruling — June 22, 2026

Washington Times — Rising tensions around the contested shoal — June 25, 2026

Türkiye Today — Philippines fear permanent seizure of Scarborough — June 22, 2026

Manila Bulletin — AFP intensifies patrols near Bajo de Masinloc — June 23, 2026