Iran has turned its ability to restrict commercial passage through the Strait of Hormuz into a potent economic weapon in the war imposed by the United States and Israel.
IMF PortWatch shows that in the seven days ending August 2, an average of only about four ships per day passed through the strait, compared with about 90 during the corresponding week of 2025. Estimated transit volume fell from 3.5 million to about 143,000 metric tonnes per day. Both indicators declined by approximately 96 percent.
This was not a temporary collapse in traffic but a sustained disruption. Since February 28, both vessel traffic and estimated tonnage have remained far below their levels in the previous year, with only brief recoveries. Tehran has therefore already demonstrated that it can impose severe disruption on commercial traffic. The question is no longer whether Iran can disrupt trade through Hormuz, but how effectively it can convert that disruption into political leverage, and for how long.
A useful framework for understanding this strategy comes from political scientists Henry Farrell and Abraham Newman, who describe how states can turn control over central nodes in international networks into coercive power, a process they call “weaponised interdependence”. In Hormuz, the critical node is physical rather than financial or digital. Geography gives Iran leverage over a corridor on which energy producers, shipping companies and importing economies remain heavily dependent.
The scale of that dependence shows Tehran’s leverage. In 2025, almost 20 million barrels of crude oil and petroleum products crossed Hormuz each day, equivalent to about one-quarter of global seaborne oil trade. Around 80 percent of those flows went to Asia. China and India alone received 44 percent of the crude oil that passed through the strait. Qatar and the United Arab Emirates also shipped liquefied natural gas (LNG) equivalent to almost one-fifth of global LNG trade through Hormuz, with no practical alternative export route.
The economic effects begin before any formal closure. Shipping companies and insurers respond to perceived risk as well as actual attacks. Even the threat of missiles, mines, drones or vessel seizures can increase insurance premiums, freight rates and waiting times. Research published in Nature Communications shows that disruptions at maritime chokepoints transmit economic losses through delays, rerouting, insurance costs and interruptions to production.
Iran can therefore exert pressure on several audiences at the same time. Gulf states face risks to export revenues, ports and logistics. Major Asian importers such as India face higher energy costs and possible supply shortages. The US imports comparatively little oil through the Strait of Hormuz, yet it remains exposed to higher global energy and domestic fuel prices, and the military costs of protecting commercial navigation. Tehran’s strongest leverage may therefore come indirectly by pushing Gulf governments and Asian importers to press Washington for de-escalation.
The consequences also extend to less obvious areas, including the emerging competition over artificial intelligence. Gulf states are investing heavily in data centres and computing infrastructure, seeking to use their access to relatively inexpensive energy to become important hubs in the global AI economy. By raising energy prices and increasing risks to Gulf infrastructure, disruption at Hormuz can raise the cost of expanding AI capacity and weaken one of the region’s central economic diversification strategies.
Hormuz also carries commodities whose importance is often obscured by the focus on oil. In our recent Nature Food study, we showed that several major agricultural economies depend heavily on fertilisers exported through the Strait of Hormuz. For example, India sources around half of its imported ammonia and nitrogen fertilisers, about nine million tonnes, from Gulf producers. Disruption would combine lower fertiliser availability with higher natural gas and shipping costs, increasing risks to crop yields and food prices in the short term, especially in food-importing countries.
Helium provides another example of this less visible dependence. Qatar and the UAE supply helium used in semiconductor production, medical imaging, scientific research and clean technologies. Helium is difficult to store, liquefaction capacity is concentrated, and there are few substitutes for several applications. Our analysis shows that several economies responsible for more than 60 percent of global integrated-circuit exports are highly dependent on helium supplied through the Strait of Hormuz. Hormuz therefore links a regional security crisis to advanced manufacturing and healthcare supply chains in Asia.
These vulnerabilities give Iran bargaining power in the war imposed by the US and Israel. Yet they also define the limits of that power.
First, disruption harms Iran itself. Iran’s petroleum exports, food imports, industrial inputs and maritime trade depend heavily on its southern waterways. Saudi Arabia and the UAE have pipelines that can redirect an estimated 3.5 to 5.5 million barrels per day away from Hormuz. These countries will therefore have stronger incentives and greater resources to expand alternative routes. Iran’s Jask route outside the strait remains effectively non-operational. A prolonged interruption would therefore deprive Tehran of export earnings while worsening inflation and shortages at home. The US blockade of Iran’s southern ports compounds this vulnerability for as long as tensions over Hormuz persist. Of Iran’s roughly 170 million tonnes of annual foreign trade, about 160 million tonnes, or 94 percent, pass through southern ports. By comparison, northern ports on the Caspian Sea handle only about 4 percent of that trade and could probably increase their share to no more than 10 to 15 percent, even in a crisis. Northern routes and sanctions-evasion networks may sustain selected shipments, but they cannot replace the southern ports as gateways for large volumes of oil, grain, steel and containerised goods.
Second, Iran can make navigation dangerous, but sustaining that disruption is costly. A US Congressional Research Service assessment concludes that Iran can disrupt shipping through mines, speedboats, submarines, shore-based missiles and aircraft, but that US forces could eventually restore traffic, although this might take days, weeks or months. Iran’s advantage therefore lies less in controlling Hormuz than in imposing uncertainty and delay. But the same uncertainty also harms its own economy: even a prolonged “no war, no peace” environment can weaken investment, government revenues and the fiscal capacity needed to sustain military pressure. Iran’s military capacity also depends heavily on public revenues, which sanctions have constrained. According to the Stockholm International Peace Research Institute (SIPRI), Iran’s military spending in 2025 was about 2 percent of GDP, compared with 3 percent in the United States and between 5 and 8 percent in Kuwait, Oman, Saudi Arabia and Israel. Iran can therefore disrupt the waterway, but it cannot sustain that disruption indefinitely at an acceptable economic and military cost.
Third, repeated use of the Strait of Hormuz as a weapon invites adaptation. Just as Iran has sought to adapt to sanctions, GCC energy producers will have stronger incentives to bypass Hormuz by expanding pipelines to the Red Sea and the Gulf of Oman. Importing countries will diversify suppliers, invest in strategic reserves and develop alternative sources of LNG, fertilisers and critical materials. Companies will re-evaluate supply chains built around a single passage.
After Russia’s invasion of Ukraine, governments, especially in the European Union, increasingly treated domestically generated renewable electricity as a security asset. The International Energy Agency subsequently raised its five-year forecast for global renewable capacity expansion by almost 30 percent, partly because energy insecurity accelerated policy support.
Such adjustments will be gradual. Alternatives cannot quickly replace oil in transport and petrochemicals, LNG in some electricity systems, natural gas in fertiliser production or helium in specialised industrial uses. Low-income countries also face financial and institutional constraints that may slow diversification and investment in renewables. Even so, persistent insecurity strengthens the economic case for projects that reduce dependence on Hormuz.
Tehran therefore faces a difficult trade-off. Limited, calibrated disruption can raise the costs of US military pressure, divide opposing coalitions and create bargaining space over sanctions and regional security. Prolonged or indiscriminate disruption would damage Iran’s own economy, alienate Asian partners such as China and accelerate investments that weaken its future leverage. Hormuz is therefore a powerful economic weapon, but one that Iran cannot use without also bearing some of its costs.
Hormuz is a powerful weapon because current dependence is high and short-term alternatives are limited. But its effectiveness has an expiry date. When that date arrives will depend on technological progress, available capital, political will and, crucially, on how aggressively Iran chooses to wield it. Iran can weaponise Hormuz to influence negotiations today. But every time it does, it gives others another reason to reduce their dependence on the strait. The more aggressively Iran wields the weapon, the faster it may blunt it.
The views expressed in this article are the author’s own and do not necessarily reflect Al Jazeera’s editorial stance.
