Despite international waters prohibiting tolls, both the US and Iran seek influence over the Strait of Hormuz for strategic leverage. While Washington aims to engineer its maritime tutelage via aggression and maintain regional dominance, Tehran uses the strait as a bargaining chip to pressure global powers, project strength and assert sovereignty amid sanctions. Control or presence in the strait symbolizes power and deterrence, not financial gain. Both nations exploit the waterway’s geopolitical importance to advance broader security and political objectives. Neutrally arguing, both Washington and Tehran erode the framework of maritime stability by shifting from’ ’a codified international rules to transactional bilateral power mechanics.’’
An American blockade of the Strait refers to US and allied naval interdiction restricting maritime traffic and trade to and from Iranian ports. In contrast, Iranian control of the strait refers to Tehran’s use of military assets to intercept, divert or halt merchant shipping. Washington seeks to protect global oil supplies by maintaining a strong security presence, supporting its Gulf allies, stabilizing energy markets and projecting regional power. Tehran, meanwhile, views the strait as a tool of sovereignty, national security and diplomatic leverage, using it to deter foreign intervention, pressure Gulf States, circumvent sanctions and influence global energy supplies during geopolitical standoffs.
According to the MoU’s article 5, ‘’The Islamic Republic of Iran will conduct dialogue with the Sultanate of Oman, to define the future administration and maritime services in the Strait of Hormuz, in discussions with other Persian Gulf Littoral States, in line with applicable international law and the sovereign rights of coastal states of the Strait of Hormuz’’. But such an arrangement was to be made after the final deal between Washington and Iran. On the other hand, despite the United States’ status as a world naval power and its longtime interest in freedom of navigation through international straits, this “hands-off” attitude is surprising. Understandably, both the US and Iran are not signatories to UNCLOS.
Needless to say, the prevailing global view is that the transit-passage regime reflects customary international law and is therefore binding on all states. Iran shares the Strait with Oman, a party to UNCLOS, which is bound to permit transit passage through its territorial waters. Any Iranian interference with passage through Omani waters would infringe Oman’s sovereignty and violate international law. Charges may be levied only for specific services rendered to a ship under Article 26 of UNCLOS and Article 18 of the 1958 Convention on the Territorial Sea, which Iran signed but did not ratify. The United States is a party to the convention.
The facts on the ground suggest that the Strait of Hormuz is a natural waterway overlaps with the territorial limits of Iran and Oman. While they are not international waters, maritime law guarantees a right of transit passage. This means that ships from all countries have the right to continuous, free and unobstructed navigation. UNCLOS prohibits blocking or taxing passage through such straits, reinforcing the principle that no state may obstruct lawful transit. Iran’s actions in the Strait have not yet amounted to a blockade, but tensions highlight the need for legal frameworks to prevent conflict. Conflict resolution can be pursued through diplomatic channels, arbitration under UNCLOS or regional cooperation.
Moreover, China has called for the restoration of safe navigation in the Strait of Hormuz amid renewed tensions between the US and Iran, emphasizing diplomatic resolution and freedom of passage. UN Security Council resolutions reaffirm freedom of navigation. However, enforcement can be blocked if a permanent member vetoes collective action. And also, The ICJ has jurisdiction in maritime disputes, such as the precedent set in the Corfu Channel Case affirming international straits must remain open. However, it requires both disputing states to consent to its jurisdiction.
Iran’s threat to block the Bab el-Mandeb Strait in the Red Sea would cause immediate global consequences. As a checkpoint for 12% of the world’s trade and 30% of global container traffic, it is of critical importance. Despite Iran suspending the Islamabad Memorandum of Understanding over alleged US violations, international diplomacy urges both sides to de-escalate and resume negotiations. Tehran suspended its obligations under the Memorandum of Understanding, alleging that Washington violated the ceasefire. Peace mediators, including Pakistan, Qatar, Turkey and KSA, are actively calling for both nations to exercise restraint and salvage the Islamabad framework by holding direct or indirect second-round talks to address the core nuclear and maritime disputes.
Given the writ of above arguments, it is pragmatic that both the US and Iran must hold a permanent ceasefire instead of expanding the conflict while indulging in a legal war over the Strait of Hormuz. What is controversial at the part of the US Administration that President Trump not only threatens to reinstate the naval blockade on Iranian ports, but also said the U.S would collect a 20 percent toll for passage in the strait as a reimbursement for security expenses for keeping it open. In the current situation, in times of declared armed conflict, the rules of transit passage shift. Belligerent states can legally interfere with adversary shipping, but the blockage of all neutral commercial traffic remains illegal under the San Remo Manual on the Law of International Armed Conflict.
In summary, make no mistake, a legal war turned into an armed conflict over the Strait of Hormuz serves no one. The US and Iran must abandon brinkmanship and restart the second round of technical talks mandated by Islamabad memorandum of understanding. This framework remains critical for rebuilding trust. However, Iran has now signaled it will not attend, highlighting deep mistrust. Reopening dialogue through diplomatic channels—possibly via third-party facilitation—could prevent further escalation and revive confidence in the agreement.
—The writer, based in Pakistan, an independent IR & International Law analyst, also a Peace and Conflict Studies expert, is member of the European Consortium of Political Research, including Washington Foreign Law Society/American Society of International Law.
