International conflicts are no longer confined to clearly defined theatres of operations; the battlelines increasingly extend to energy and transportation infrastructures, including maritime routes.
At the centre of the war of the US and Israel against Iran and the current pause for negotiations lie instruments of pressure employed by both sides. Iran is taking advantage of its proximity to the Strait of Hormuz, a maritime chokepoint that it has transformed into an instrument of control.
Geography has thus become a means to exert pressure on a vital artery in the world’s supplies of energy, food, fertilisers, and medicine. This has prompted the US to initiate a naval blockade of Iran, beginning on 13 April, with the aim of seizing control of Kharg Island, Iran’s main petroleum export terminal.
Approximately 90 per cent of Iran’s oil exports pass through this island, making it a key leverage point in compelling Tehran to reopen the strait.
The Strait of Hormuz extends between Iran’s southern coast on the one side and the northern coast of Oman, particularly the Musandam Peninsula, on the other. At its narrowest point, it is about 21 nautical miles wide, expanding to roughly 27 at its entrances.
With approximately one-fifth of the global consumption of petroleum and liquefied natural gas (LNG), about 20 million barrels a day, and roughly one-third of global fertilisers passing through it, the strait occupies a key position in the global economy.
It is little wonder that it lies at the heart of the current conflict as a key factor in economic and strategic deterrence.
The strait’s significance extends beyond its geographic role as a link between the Arabian Gulf and the Gulf of Oman and the Arabian Sea and the Indian Ocean. It is a waterway where regional sovereignty intersects with international interests, and where legal frameworks intertwine with geopolitical considerations.
These are particularly complex in a region marked by political and military tensions between Iran on the one side and the Gulf states and major powers, especially the US, on the other.
Hormuz has also previously been the focus of numerous confrontations between Iran and the US and its allies. During the Tanker War that took place as part of the Iran-Iraq War (1980-1988), both sides targeted oil tankers belonging to the other side and to their respective allies in the Gulf, prompting international intervention to protect navigation.
This was followed by Operation Praying Mantis (1988), a military confrontation in the Gulf between the US Navy and Iran, during which the US destroyed a significant portion of Iran’s fleet after a US vessel was damaged by a mine.
In the 2010s, the intensification of Western sanctions against Iran was met by repeated Iranian threats to close the strait and then by the harassment of US warships by Iranian Revolutionary Guard Corps (IRGC) boats.
Following the US’ unilateral withdrawal from the international nuclear agreement with Iran in 2018, tensions in the Gulf escalated further, erupting in the 2019-2020 tanker crises – attempts by Iran to seize oil tankers, such as the British-flagged Stena Impero, and other vessels, prompting military escalation that culminated in the intervention of a UK Royal Navy frigate.
Another major escalation occurred after 2024, when Iranian threats to close the strait came against the backdrop of an unfolding regional war with global repercussions, as reciprocal strikes disrupted shipping and drove up energy prices.
The current war demonstrates more clearly than ever how control over the strait can be converted into a strategic lever. The mere threat to close it can cause chaos in global markets. Threats to shipping spark increases in shipping and insurance costs, wild price fluctuations, and disruptions to the supply chains relied upon by major industrial economies.
This is especially true of Asia, which receives the largest share of oil and gas exports passing through this narrow maritime corridor.
INTERNATIONAL LAW: Maritime obstruction in the strait raises questions concerning the legal regime governing it and the limits of the coastal state’s authority.
The Strait of Hormuz is considered to be a strategic international strait subject to the “transit passage” regime outlined in Articles 37-44 of the 1982 United Nations Convention on the Law of the Sea (UNCLOS). This guarantees the right of continuous and expeditious transit for all ships between one part of the high seas or an exclusive economic zone (EEZ) and another, without interference from littoral states, in this case Iran and Oman.
According to this regime, territorial waters in international straits are not subject to absolute national sovereignty. As stated in Article 26 of UNCLOS, no charges may be imposed on foreign vessels merely for passing through the strait, meaning that any fees imposed by Iran, as it has threatened to do, would violate international law.
Iran might plead political or moral reasons for levying transit fees, but it would have no legal grounds under the transit passage regime. This is in contrast to artificial canals such as the Suez, Panama, or Kiel, which fall entirely under the sovereign control of a single state.
Iran, however, claims the right to apply the concept of “innocent passage”, which applies to the coastal waters of states in general. Under this regime, vessels of all states may navigate through another state’s territorial waters in a continuous and expeditious fashion for the purpose of transit, entry into internal waters, or exit from them – provided that such passage does not jeopardise the peace, security, or public order of the coastal state or involve activities detrimental to its sovereignty or vital interests.
As the territorial waters are deemed to fall under the absolute sovereignty of the coastal state, the passage of foreign vessels remains subject to the laws and regulations of that state, as applied within the limits of international law. Iran is not a party to UNCLOS and therefore bases its position on the concept of non-suspendable innocent passage as laid out in the 1958 Geneva Convention on the Territorial Sea.
In March, Iran attempted to impose transit fees of up to $2 million on certain vessels, citing its 1993 domestic legislation titled “The Law of the Maritime Areas of the Islamic Republic of Iran”.
Under this law, Iran unilaterally delineated its territorial sea, including parts of the Strait of Hormuz, on the basis of a baseline calculation that incorporates several islands on both sides of the strait, among them the three disputed islands of Greater Tunb, Lesser Tunb, and Abu Musa, which Iran took control of in 1971 following the independence of Oman, the UAE, Qatar, and Bahrain from British rule.
The law organises navigation in the strait according to the principle of innocent passage, allowing Iran to regulate passage through its territorial waters in line with its economic, security, and national interests. This includes the ability to levy transit fees and to require prior authorisation or notification for certain vessels.
In practice, the standard of “innocence” is a flexible instrument capable of incorporating considerations of national security, maritime safety, and environmental protection into the assessment process. This effectively expands the state’s discretionary authority beyond regulating passage to controlling its conditions and limitations, thereby transforming passage from a guaranteed right into a conditional legal status.
This situation has sparked international controversy. Shipping experts have described the Iranian actions as a form of “global extortion”, a violation of Iran’s international obligations, and an unprecedented attempt to impose “tolls” on an international maritime corridor.
The international community agrees that Hormuz falls under the more permissive transit passage regime, an international legal framework that denies any single state sovereign control over the strait. However, the situation is complicated by the fact that neither Iran nor the US has ratified UNCLOS, leaving room for conflicting interpretations regarding how binding its provisions are.
Iran grounds its position on the fact that it is not a party to this convention and therefore that the strait falls under its full sovereignty. This entitles it to take all necessary measures for self-defence, including closing the strait to navigation, it says.
SECURING THE STRAIT: The US must contend with certain challenges if its naval blockade is to succeed in securing the Strait of Hormuz.
The first is geography: the strait’s narrow width hampers the manoeuvrability that warships require to evade missiles and drones. In addition, the rugged Iranian coastline overlooking the strait possesses natural caves, from which relatively small Iranian forces can easily fire on hostile targets. The mountainous terrain also provides a degree of protection from airstrikes as well as an elevated vantage point for monitoring ship movements.
The second challenge is posed by the Iranian arsenal: anti-ship cruise missiles, unmanned surface vessels, unmanned underwater vehicles, ballistic missiles, and “Shahed” drones capable of flying low over water, making them difficult to track and intercept. Iran also possesses “low-cost and high-impact” naval mines, some of which are mobile.
The IRGC has accumulated decades of experience in mine warfare, including the use of deceptive tactics, as reflected in Iranian reports of the “drifting mines” it has deployed in the strait.
The third challenge lies in the IRGC’s increasingly decentralised command-and-control structure. A strategy adopted to ensure operational resilience, this naturally suits Iran’s defensive tactics in and around Hormuz but complicates the tasks of US-Israeli surveillance and control systems.
According to some analysts, one of the main options under consideration by the US is to assert partial military control over the strait, using Marine forces supported by naval units, aircraft carriers, and missiles.
The proponents of this scenario argue that this military control would not constitute territorial occupation of sovereign territory in the conventional sense, but rather would be a precautionary and proportionate measure required to restore the strait to its proper legal status. Thus, it is not an act of aggression against Iranian sovereignty, but a legitimate means of enforcing international law and protecting freedom of navigation.
The operation would be further framed as a response to Tehran’s violations of its maritime obligations. Some have characterised these violations as a form of “sovereign piracy”, entailing the effective subjugation of an international waterway to Iran’s arbitrary control without a legal foundation, thereby threatening freedom of navigation as a collective global interest.
The politicisation of strategic waterways, such as the Strait of Hormuz, constitutes a pressing threat to the region and the world at large. Such waterways must be fully insulated from political machinations and transformed into international facilities governed by stable rules.
This must apply to Hormuz in the post-war phase, whether the conflict between the US-Israel axis and Iran ends through a negotiated or military resolution. Whatever political settlement is reached, it must include an explicit commitment to keeping the strait fully open without interruption.
This commitment must be backed by clear enforcement mechanisms – whether through international arrangements or regional coordination – that guarantee sustained freedom of navigation and prevent future politicisation of the strait.
* The writer is Head of Arab and Regional Studies in Ahram Center for political Studies
* A version of this article appears in print in the 16 April, 2026 edition of Al-Ahram Weekly.
Short link: