A week ago, Houthi forces reached the island of Perim, situated in the centre of the Bab el-Mandeb Strait, after Yemeni government forces had withdrawn, ceding the entire western coast of Yemen. An 18-hour lightning offensive – the port of Mokha, the Hanish and Zuqar islands, then Perim – and one of the world’s most strategic chokepoints changed hands.

This is not an isolated incident in the Yemeni conflict. It is the second phase of an Iranian strategy that has been taking shape for months. The first phase was Hormuz, the northern gateway to the Gulf, which has been under pressure since February 2026 and where shipping traffic has now fallen below ten vessels a day. The second is Bab el-Mandeb, the southern gateway to the Red Sea. With both under hostile control, Tehran holds a geopolitical lever unprecedented in the recent history of the Middle East.

The link between the two straits is no mere geographical coincidence. The Houthis are Iran’s most advanced proxy force in the region, funded, armed and led by Tehran as part of a specific regional strategy. On 16 July 2026, Iran had already explicitly asked the Houthis to close the Bab el-Mandeb Strait in the event of further American attacks on its infrastructure. The Pasdaran have deployed dozens of advisers to assist with the current offensive. Khamenei’s adviser has already publicly hailed the “resounding victory” in the Red Sea. This was not an autonomous Houthi move: it was an Iranian move carried out by the Houthis. And almost no one in Europe is interpreting it as such.

The model: monitoring without shutting down

The Houthis’ strategy is not to close the strait, at least not in the immediate future. It is a replica of the model Iran has applied in the Strait of Hormuz: taking physical control of the chokepoint, declaring that navigation is ‘free and safe’ for everyone except designated enemies, and waiting for the new reality to become the norm before using this leverage more aggressively.

The model has three distinct phases. The first is physical control: coastal territory, strategic islands, and positions that command the passage. The second is the reassuring statement – the Houthi spokesperson has already said that navigation is‘safe for everyone except Saudi ships’– which serves to reduce immediate international pressure and give the international community time to come to terms with the change. The third phase, which has not yet taken place but which the logic of the model makes predictable, is monetisation: tolls, service charges, transit authorisations. Not closure, but control. Not a blockade, but leverage.

The Iran-Oman agreement of 25 August on the Strait of Hormuz has already formalised this arrangement: not a reopening of the strait, but a new control regime under which traffic entering the Gulf passes through Iranian waters under Iranian surveillance, whilst departures are authorised by Muscat following notification to Tehran. This is not freedom of navigation in the sense of international law: it is freedom of navigation granted by whoever physically controls the passage, on the terms they determine. Bab el-Mandeb will follow the same path.

Because it sets a precedent and is not an isolated incident

International law on freedom of navigation is based on a principle that has underpinned the global maritime system for decades: international waterways belong to no one, and no actor may impose unilateral conditions on transit. The 1982 United Nations Convention on the Law of the Sea establishes the right of transit passage through international straits as a peremptory norm, from which no unilateral action may derogate.

What Iran and the Houthis are building is an alternative system: de facto control of a chokepoint as a substitute for legal title. They do not claim sovereignty over the strait in the sense of international law; they control it in practice, which produces equivalent effects without having to face the consequences of a formal claim. It is more sophisticated than a mere violation of international law: it is the replacement of that law with a de facto system that produces the same effects without providing opponents with the legal grounds for a direct challenge.

A precedent is established not when it is declared, but when it is tolerated. This is the mechanism described in strategic communication as ‘the governance of communication’ – the ability to control not individual messages but the interpretative environment within which any message is received, as set out in *Governare il linguaggio* (D’Andrea, 2026). One does not change formal law: one constructs a context in which operating outside that law is no longer perceived as an extraordinary violation, but as the new normal. Every day that passes without a systemic response is a day in which the new de facto regime becomes entrenched. And once it is entrenched, the cost of challenging it becomes prohibitive.

Who has an interest in challenging it, and who does not

The United States has an interest in challenging Iran’s control of the Strait of Hormuz because it affects energy prices on American markets. It has no immediate interest in challenging the Houthis’ control of Bab el-Mandeb because that strait primarily serves trade between Europe and China. Trump implied this when he rejected the military intervention requested by Riyadh.

China has an interest in ensuring freedom of navigation through Bab el-Mandeb – it is its export route to Europe – but prefers to play the long game: not to challenge the precedent openly, to let others bear the cost of the crisis, and to present itself as a mediator when the time is right. It is the same strategy applied in the Strait of Hormuz.

Europe is the continent most at risk and the one with the slowest response. Paradoxically, it is also the one that would have the most to gain from challenging this precedent in a systematic manner: not only for the sake of immediate commercial interests, but because a robust system of international maritime law is a structural prerequisite for the European economic model. Europe thrives on trade. European trade thrives on sea routes. Sea routes thrive on freedom of navigation. If that freedom becomes a discretionary concession granted by those who physically control the chokepoints, the European economic model faces a structural problem that no industrial policy can compensate for.

What would it take to challenge the precedent?

Challenging this precedent requires a systemic response on three simultaneous levels, each of which is necessary but none of which is sufficient on its own.

From a legal perspective, bringing the matter before the International Tribunal for the Law of the Sea by documenting the violation of the transit passage regime, and building a coalition of countries that formally refuse to recognise the new de facto regime. This will not produce immediate results, but it shapes the interpretative framework within which the precedent is understood by the international community, thereby preventing normalisation from proceeding unnoticed.

On the diplomatic front, coordinate with China, India, Japan and South Korea to establish a common position that explicitly rejects the principle of quasi-state control over international chokepoints. China has a direct commercial interest in the route: involving it is not a pipe dream, it is a calculated move. This is not a military alliance: it is a coordinated political statement that increases the reputational cost of setting a precedent for those who are creating it.

At an operational level, a coordinated military response cannot be ruled out – quite the contrary. Updating the mandate of existing European naval operations to reflect the new reality is the bare minimum: Atalanta and Aspides were designed to combat piracy and escort ships in transit, not to respond to quasi-state territorial control of an international chokepoint. But if Houthi control becomes entrenched and the process of monetising the strait begins, a coordinated military response involving European, American and regional forces – with a clear mandate and an internationally legitimised coalition – becomes not only feasible but necessary. The Iranian precedent regarding chokepoints cannot truly be challenged unless it is also challenged in terms of military force. Deterrence works when it is credible, and credibility is built before the cost of intervention becomes prohibitive, not afterwards.

The precedent is only overturned if it is challenged. And it is only challenged if someone decides it is worth the effort before it is too late to do so at an acceptable cost.