The Hormuz Blockade: War behind the ceasefire

On 13 April 2026, the United States Central Command announced a naval blockade of Iranian ports in the Arabian Gulf and the Gulf of Oman. Since then, the Pentagon reports that 23 ships have already been turned back, and a US destroyer has opened fire on and seized an Iranian vessel that tried to evade the blockade.

America justifies these actions as self-defence. Iran calls them an act of war. And the world-from Beijing to Brussels, from Dhaka to Mombasa, watches in disbelief as oil prices surge past $100 a barrel, hundreds of ships remain stranded, and a fragile ceasefire is mocked by the very nation that pretends to uphold it.

The most glaring absurdity of this crisis is the US administration’s attempt to have it both ways. On one hand, Washington declares a ceasefire and extends it for an indefinite period, and pretending intention to negotiate in good faith. On the other, it simultaneously imposes a naval blockade, an act that international law has long recognised as an act of war.

This is not a matter of interpretation. The UN General Assembly’s Definition of Aggression (1974) explicitly states in Article 3(c) that “the blockade of the ports or coasts of a State by the armed forces of another State” constitutes an act of aggression. You cannot blockade a nation’s ports and simultaneously claim you are at peace with it. You cannot throttle a country’s economy and insist you are pursuing diplomacy. This is not statecraft. It is strategic self-contradiction and it is dangerous play.

The ceasefire represented a pause in active hostilities. By imposing a blockade while that pause was still in effect, the United States has not merely violated the spirit of the ceasefire, it has fundamentally betrayed itself.

The US administration will undoubtedly invoke Article 51 of the UN Charter, the right of self-defence, to justify its actions of preemptive strike and blockade. But Article 51 is clear, self-defence applies only “if an armed attack occurs” against a member state. It does not authorise anticipatory strikes, economic strangulation, or the unilateral imposition of a blockade.

The International Court of Justice has repeatedly held that the prohibition on the use of force in Article 2(4) of the Charter is a peremptory norm of international law, a norm from which no state can derogate.

What armed attack, precisely, is the United States responding to? The narrative is shifting by the day, but no credible evidence has been presented of an imminent Iranian threat that would justify a full-scale attack or the imposition of naval blockade. In fact, the blockade itself has become the primary source of escalation. As Iranian officials have argued, and as the world’s major powers increasingly acknowledge, this blockade is not a defensive measure but an aggressive act designed to cripple Iran’s economy, using deprivation as a weapon of coercion.

Even if one were to set aside the fundamental illegality of the blockade under the UN Charter, the manner in which it is being enforced raises additional violations of the law of the sea. The blockade zones, as CENTCOM has described them, extend into the whole of the Gulf of Oman and the Arabian Sea, areas that constitute high seas under the 1982 United Nations Convention on the Law of the Sea. Article 87 of UNCLOS guarantees the freedom of navigation on the high seas for all states. No nation has the right to unilaterally impose conditions on “other ships and aircraft” in these waters.

Yet the US blockade does precisely that, applying to vessels of all nations entering or departing Iranian ports and coastal areas. This is not a targeted interdiction of specific military contraband. It is a blanket prohibition that treats every vessel, every cargo, every sailor as a potential enemy. It is the very definition of overreach, and the international community knows it.

America’s European allies are not rallying to its side. Nobody has raised their hands to join the US in the blockade. The silence is telling. Traditional partners are keeping their distance, unwilling to endorse an act that carries all the hallmarks of aggression rather than defence.

Meanwhile, the costs are being borne by everyone else except the US and its trusted ally-Israel for whom the US is fighting the war. The Strait of Hormuz carries roughly 20 per cent of the world’s oil supply. With the blockade sharply curtailing traffic through this vital chokepoint, energy prices surged. Hundreds of ships remain stranded at either end of the strait, awaiting clearance. Shipping agents are warning of further supply chain disruptions, raising freight costs and fuelling inflation across the globe.

China and Russia have vetoed a UN Security Council resolution on the strait, with Beijing slamming the blockade as a threat to global stability. China, a major importer of Iranian oil, is feeling the economic pain. So is India. So is Dhaka. So is Kenya. So is every nation whose economy depends on predictable energy flows through the Strait of Hormuz and open and rule based sea lanes.

Beyond the legal arguments, there is a moral dimension that the United States cannot escape. Naval blockades, by their nature, inflict suffering not merely on military targets but on entire populations. Food, medicine, and other essentials, goods that have no legitimate military purpose-inevitably become a catch in the net. The San Remo Manual on Armed Conflicts at Sea explicitly suggests that a blockade is prohibited if its sole purpose is to starve the civilian population or to deny it objects essential for survival.

The US administration has offered no guarantee that humanitarian supplies will be permitted to reach the Iranian people. It has offered no mechanism for impartial oversight. It has offered only the vague promise that the blockade applies only to vessels ‘entering and exiting Iranian ports’, offers little comfort to a civilian population dependent on imported food and medicine.

The blockade of Iranian ports is not a measured act of self-defence but a deliberate act of war dressed in legal ambiguity. By imposing a naval blockade while simultaneously claiming to uphold a ceasefire, the United States has exposed a dangerous contradiction at the heart of its foreign policy, one that undermines the very foundations of international law. The UN Charter, the Law of the Sea, and decades of precedent all converge on a single truth: unilateral blockades are acts of aggression, not instruments of peace.

Yet beyond the legal violations and geopolitical manoeuvring lies a more urgent reality. The world is paying the price, not only in soaring oil prices and stranded ships but in the erosion of the rules-based order that has, however imperfectly, restrained great-power conflict for nearly eighty years. If the international community permits this blockade to stand without consequence, it invites a future where might alone defines right, where ceasefires become tactical pauses rather than genuine commitments, and where the distinction between defence and aggression dissolves entirely.

The ceasefire was already fragile. The blockade has shattered it. The question now is not whether the United States has violated the law, it has, but whether the rest of the world will have the courage to say so plainly and act accordingly. Silence is complicity. And in a world where twenty per cent of global oil passes through the Strait of Hormuz, complicity carries a price no nation can afford to pay.

* Mohammad Abdur Razzak ([email protected]), a retired Commodore of Bangladesh, is a security analyst.

* The views expressed here are the author's own.