“Tanker for tanker”: How did oil tankers become weapons in the US-Iran war?

Abu Dhabi, UAE – Between tankers being struck, others changing course, and cargo being transferred from ship to ship outside the Strait of Hormuz, the US-Iranian conflict is no longer measured solely by the number of missiles, but also by the number of ships able to pass through. The battle for the Strait of Hormuz is no longer just a confrontation between American and Iranian missiles. In recent hours, the conflict has entered a different phase after US forces targeted two Iranian oil tankers, a move that US sources said was part of a new policy dubbed “tanker for tanker.”

According to US reports, Washington targeted the two tankers in retaliation for Iranian attacks on commercial vessels in the Strait of Hormuz, marking the first publicly acknowledged shift from intercepting ships or imposing blockades to targeting Iranian tankers as a deterrent. Ironically, the tankers targeted in this equation are not necessarily military vessels; they are part of the world’s energy lifeline. And here lies the more serious question: what happens when every oil tanker becomes a potential military asset?

From “protecting navigation” to “tanker against tanker”

The American shift carries significance beyond the strike itself. Until now, Washington had said its primary goal was to secure navigation and prevent Iran from using the strait as a weapon. But targeting Iranian government tankers in response to attacks against commercial ships takes the equation to another level: every attack on a ship could result in a direct price on an Iranian ship. American reports say that the new policy was approved by President Donald Trump with the aim of deterring Iran from targeting ships passing through Hormuz. Thus, the tanker turns into something like a “strategic hostage”: its value is not only in the oil it carries, but in its ability to force the other party to think twice before attacking its opponent’s ship.

Iran did not start from scratch.

But the idea of ​​using ships to pressure an adversary is not new in the current conflict. In August, Iran threatened to take action against 45 tankers it said had violated Tehran’s transit rules, including fines, detention, and confiscation of cargo. The list included oil and gas tankers and petroleum product vessels linked to various companies and countries. More seriously, Tehran did not stop at threatening detention; it expanded the scope of the penalty to include ship-to-ship oil transfers if one of the vessels was on Iran’s sanctions list. This means the battle is no longer just about who passes through the Strait, but about who has the right to set the rules of passage and who can impose the price for violating them.

Two Saudi tankers… and the message has reached the market.

The day before the US strike on the two Iranian tankers, two giant tankers carrying Saudi oil were attacked with projectiles as they exited the Strait of Hormuz. The Saudi tanker Sidr and the Liberian-flagged Senegal Prosperity, carrying a combined total of approximately 4 million barrels of Saudi crude, were attacked minutes apart near the Omani coast. No one claimed responsibility for the attack. This highlights the danger of a “tanker-for-tanker” approach: if commercial vessels themselves become part of the equation of retaliation, any attack on a tanker may not be confined to the sea; it could escalate into a strike on an oil facility, tanker, or port on the other side. The sea becomes a battleground, the tanker becomes a target, and the price of oil becomes an indicator of the attack’s success.

Hormuz: When ship movements become a measure of war

The figures reveal the extent of the shift. On Tuesday, only four commercial cargo ships transited the Strait of Hormuz, compared to an average of about 13 over the previous ten days, according to preliminary data from Kpler. Three were departing and one was entering. The day before, no liquid tankers were recorded passing through the strait, although a limited number of other vessels did. These figures don’t necessarily mean that all ships stopped; some vessels switch off their tracking devices during transit. However, the significant decrease reveals something more important: shipping companies are now treating Hormuz as a genuinely dangerous area, not just a tense waterway.

Oil is no longer just a commodity.

As the number of ships decreased, the price of oil rose due to fear. Brent crude jumped by more than $4 on Tuesday, settling at around $94.65 a barrel, while West Texas Intermediate (WTI) crude rose to around $90.22. On Wednesday, oil continued its upward trend, with Brent reaching around $95.68. The reason is not only the potential destruction of oil facilities, but also the possibility that transporting oil itself will become more difficult and expensive. Before the war, the Strait of Hormuz carried approximately 20% of the world’s oil consumption, making any prolonged disruption there a problem that extends beyond Iran, the United States, and the Gulf states.

A tanker that doesn’t pass may be more valuable than a tanker that is attacked.

The greatest damage may not even require a ship to be hit; it is enough for a shipping company to decide that passage has become costly or dangerous. Marine insurance provides a clear example: the cost of war risk insurance in the Strait of Hormuz rose during July to approximately 7.5%–10% of the ship’s hull value, up from 1%–3% before the risk escalation. Thus, the new equation becomes: one missile → higher risk → more expensive insurance → more expensive shipping → more expensive oil. In other words, a ship can achieve a military objective even if it is not hit at all.

Therefore, the tankers began to hide.

One of the most unusual aspects of the war is that some oil shipments have begun shifting from open sea to less vulnerable areas. Ship-tracking companies have detected ship-to-ship transfers of Saudi cargoes outside the Strait of Hormuz, particularly off Fujairah and Sohar, with some tankers switching off their tracking systems to reduce the likelihood of being targeted. In the liquefied natural gas (LNG) sector, an even more peculiar practice has emerged: ship-to-ship transfers of LNG outside the strait, a rare occurrence for this type of shipping, aimed at delivering Qatari and Emirati gas to India and Japan despite the disruption of the traditional route. Here, the war resembles a game of “cargo concealment”: the ship moves, but its location is not disclosed; the cargo doesn’t stop, but is transferred to another vessel; and the route isn’t officially closed, but in practice, it becomes less frequently used.

Iran loses oil, but gains leverage.

Ironically, Iran’s strategy regarding the Strait of Hormuz is backfiring. According to Reuters, for nearly seven weeks, Iran has been unable to export significant quantities of crude oil through the strait, with Iranian loadings plummeting from approximately two million barrels per day in March to between 220,000 and 255,000 barrels per day in August. However, Tehran appears willing to bear some of this cost in order to maintain leverage over its adversaries. If Iran cannot easily export its own oil, it can at least make it more difficult for others to export theirs. The equation then becomes: “If I cannot use Hormuz, it won’t be free for my adversary to use it.”

America faces a different dilemma

Washington can strike Iranian tankers, but it cannot guarantee that every strike will remain limited. If Iran responds to an American tanker or one linked to the United States, and then Washington responds to an Iranian tanker, the war could enter into a cycle of escalation that is difficult to control. This is the real danger of the “tanker for tanker” policy. Because it creates a new mathematical equation: an attack on a ship = a retaliatory strike = a new attack = a larger strike, and over time the boundaries between “protection of navigation” and “war on navigation” may disappear.

The hidden winner: alternative methods

The crisis has begun to push the Gulf states to consider something that once seemed costly and unnecessary: ​​redrawing the map of oil and gas exports away from the Strait of Hormuz. Saudi Arabia and the UAE are working to bolster alternative ports, pipelines, and routes that are not entirely dependent on the strait, while the importance of Fujairah and ports outside Hormuz has increased. In Jordan, transit traffic through the port of Aqaba jumped by 155.1% in the first half of 2026 compared to the same period in 2025, with some trade destined for Iraq shifting overland instead of through Gulf ports. Thus, the war may achieve a far-reaching strategic outcome that was not on its agenda: forcing the region to seek a world less reliant on Hormuz.

The most serious question is: What if every tanker becomes a “legitimate target”?

Here, the war enters a highly dangerous phase. The International Maritime Organization (IMO) has condemned attacks and threats against commercial vessels since the beginning of the crisis, emphasizing the need to respect navigational rights and maritime freedoms under international law. However, on the ground, commercial vessels are caught between two powers: Iran wants to impose rules of passage and deter violators, while the United States wants to enforce a safe passage by force and protect ships, using Iranian tankers as leverage. Shipping companies, on the other hand, cannot afford to engage in the conflict; they have crews, cargo, insurance, shareholders, and delivery contracts. Therefore, the decision of the captain or the insurance company may prove more important than the general’s in determining the future of the Strait of Hormuz.

A war that doesn’t require sinking a tanker

The most significant shift is that modern naval warfare doesn’t require sinking ships to achieve its objectives. It suffices for a tanker to stop, change course, switch off its tracking device, incur higher insurance costs, transfer its cargo to another vessel, or cause a surge in oil prices. In such cases, the war has already achieved its economic impact before the missiles even reach their target. Therefore, “tanker for tanker” is not merely the name of a new American policy of retaliation; it is a model of maritime economic warfare where missiles follow ships, and markets follow the missiles.

Who wins the tanker game?

If the equation persists, the question will no longer be simply: Who can strike whose tanker? The more crucial question will be: Who can keep their tankers at sea? Iran possesses the geography and the ability to threaten the Strait, but it loses a portion of its oil exports. America possesses naval and air power and the ability to protect shipping lanes, but it cannot force the global market to ignore the risks. The Gulf states possess oil, but they have discovered that possessing oil is insufficient if the route to it and to markets becomes a vulnerability. Shipping companies, however, are the ones who pay the price directly. Ultimately, the real battle in the Strait of Hormuz may not be between an American ship and an Iranian one, but between a “ship that can sail” and a “ship that cannot afford to sail.” And here lies the most difficult question: Have America and Iran initiated a new war in Hormuz, one in which not only oil but also the tankers themselves are the ammunition?