What is the Iran-US Conflict in the Strait of Hormuz?

Soon after a temporary ceasefire came into effect between Iran and the United States, tensions shifted to the Strait of Hormuz. When Iran refused to restore maritime transit conditions to their pre-war state, U.S. President Donald Trumpannounced a naval blockade in the Persian Gulf. He said that no ships would be allowed to enter or leave Iranian ports for international waters, except those carrying essential supplies like medicine and food.

At present, Iranian maritime movement in the region has almost come to a halt. In response, Iran said it would block any ships linked to the U.S. government - given that the two countries remain in a state of war—from passing through the Strait.

The Blockade as a Tool of Pressure

Under United Nations General Assembly resolutions, a naval blockade is typically seen as an act of war and a form of military aggression. Despite this, the Islamic Republic has not officially reacted to the U.S. move. Instead, it has avoided calling the blockade a violation of the ceasefire brokered by Pakistan, possibly to prevent a fresh escalation.

From the U.S. perspective, the blockade is a classic pressure tactic - cutting off economic activity to force concessions. Washington also aims to restore “normalcy” in the Strait, which had been disrupted by Iranian attacks on shipping during the conflict. Any attempt to block access to this international waterway or impose “tolls” is considered illegal under international law.

The Legal Battle: 1958 vs. 1982

The Strait of Hormuz is one of the most critical maritime routes in the world, with around 100 to 140 large vessels passing through it daily before the war. Its legal status, however, has long been disputed.

The 1982 United Nations Convention on the Law of the Sea introduced the idea of “Transit Passage,” which allows both military and commercial vessels and aircraft to pass through international straits without interruption. In return, coastal nations were allowed to extend their territorial waters up to 12 nautical miles (around 20 km).

At its narrowest point, the Strait is about 21 miles wide, meaning it lies entirely within the territorial waters of Iran and Oman. While Oman is part of UNCLOS and supports Transit Passage, neither Iran nor the United States has signed the agreement.

Iran instead follows the 1958 Geneva Convention, which defines “Innocent Passage.” Under this stricter framework: Warships and military aircraft must seek prior approval from coastal states, submarines must remain on the surface, and passage can be denied if it is seen as “prejudicial to peace and security.”

A Global Economic Dilemma

The U.S. maintains that Transit Passage has evolved into “customary international law,” meaning it should apply even to countries that are not signatories to the 1982 convention. Both legal frameworks, however, agree on one core idea: no country can claim complete control over an international strait or unilaterally rewrite its rules.

So far, the United Nations Security Council has not officially labeled Iran’s actions as a “threat to international peace,” largely because Russia and China blocked a draft resolution proposed by Bahrain. Meanwhile, the International Maritime Organization has taken a more direct stance—calling Iran’s actions a violation of navigation freedom while also describing the U.S. blockade as illegal.

The Future of the Waterway

For now, the situation remains unstable for both sides. As a natural passage connecting the Persian Gulf to the Sea of Oman, the Strait of Hormuz cannot be fully controlled by any single power.

Ultimately, whether through diplomacy or escalation, the situation will likely have to return to its pre-“Epic Rage” (Khoshm-e Hamasi) state, when ships could pass with relative ease. Any long-term change would require a major shift in international maritime law - something that would likely face strong resistance from the global community, especially Arab states along the Gulf.