Already heavily bombed by US and Israeli forces for six weeks, Iran on 8 April narrowly avoided yet another direct showdown with Washington just hours before President Donald Trump’s deadline to reopen the Strait of Hormuz or face what he threatened would be destruction “in one night”.

Tehran complied and a two-week ceasefire began.

Yet the ceasefire has brought little relief to commercial shipping. More than 1,000 tankers and cargo vessels remain stranded in the Persian Gulf and, since the truce took effect, only four have crossed the Strait of Hormuz. The obvious question is why ships are still not moving even after the ceasefire was announced.

Crypto tolls

The answer, apparently, is a price. Shipowners are being asked to pay $1 a barrel, or as much as $2m a tanker, upfront in cryptocurrency, under terms validated by Iran’s Revolutionary Guard Corps. The cost of attempting the passage without the IRGC’s agreement is already visible in the insurance market. Before the war, cargo insurance rates were typically about 0.1% of insured value. They then surged to as much as 7.5% and are now quoted at roughly 3.5% to 4%, a rise of up to 40 times. For shippers desperate to move vessels out of a conflict zone, the choice is stark: refuse to pay and risk being attacked mid-passage, or pay up and risk breaching US sanctions on Iran.

The ceasefire, in other words, may have paused the threat of direct confrontation between Tehran and Washington, but it has not restored freedom of navigation. Safe passage through one of the world’s most important energy chokepoints no longer appears guaranteed by international convention, but negotiated through a parallel financial system beyond the reach of the greenback. Shippers are caught between extortion and enforcement.

Iran’s leverage

For Iran, the immediate objective may look like cash, but the larger aim is to test the limits of its leverage over shipping, oil markets and the willingness of the US and its allies to enforce sanctions when energy security is at stake. Despite war damage and far fewer conventional advantages, Tehran can still exert power through geography alone.

The congestion strengthens that hand. Even if the strait were fully reopened overnight and no further incidents occurred, moving more than 1,000 vessels through such a narrow passage would take at least four to six weeks, well beyond the two-week ceasefire. Hundreds of ships could therefore remain stuck in the Gulf when the truce expires on 22 April. In effect, the ceasefire is little more than a show for both sides, and both know it.

Why crypto works

Crypto is central because it offers Tehran the easiest workaround to US sanctions. Traditional dollar clearing depends on correspondent banks, regulated intermediaries and a payments system in which Washington and its allies retain visibility and enforcement power. Crypto, particularly when routed through non-US exchanges, self-custodied wallets, over-the-counter brokers and stablecoins, weakens those checkpoints. It does not make money invisible, but it can make enforcement slower, patchier and more dependent on persuading third countries and private platforms to co-operate.

That is what makes the arrangement effective. Iran is forcing shipping companies to choose between two risks: the operational danger of being stuck, harassed or attacked in the Gulf, and the legal danger of exposure to US sanctions. Crypto sits squarely in that gap, offering Tehran a payment method that is fast, portable and harder to police than bank transfers, while giving shippers just enough deniability to consider using it.

So, what next

That leaves Trump with fewer clean options than his rhetoric suggests. He cannot simply order Iran to stop charging for passage because the risk is borne by shipowners, insurers and charterers, not by the White House. Nor is it clear that another military threat would resolve the problem quickly. More force might deter Tehran at the margins, but it would do little to clear the backlog, reassure insurers or persuade operators that the route is safe again.

A naval escort operation could help, but it would be costly and limited. Escorts may reduce the risk of direct attack, but they cannot remove the wider risks of delay, retaliation or informal obstruction. Washington could also tighten secondary sanctions, target crypto channels more aggressively and warn the industry that any payment to Iranian-linked entities will carry consequences. But that would raise the cost of paying without making passage itself any safer.

Iran, by contrast, has an incentive to preserve ambiguity. It does not need to close the strait outright to retain leverage. It can keep the fee in place, selectively let some vessels through and vary the price according to political signals, turning passage into a rolling negotiation with the shipping market.

That is what makes the impasse so difficult. Both sides benefit, in different ways, from uncertainty. Trump, a self-proclaimed master dealmaker, has repeatedly shown a willingness to change course abruptly in the middle of a crisis, shifting from threats to reprieves and back again with little warning. Planning around that is a fool’s errand. Tehran, for its part, gains by keeping the market unsure how long the fee will last, how rigorously it will be enforced and whether the ceasefire itself will survive.

Even if the strait is nominally open, uncertainty alone can keep ships at anchor. Unless Washington can offer shipowners credible protection and legal certainty, and unless Tehran decides that restoring trade serves it better than taxing it, the Gulf may remain open in theory but paralysed in practice.

The question is no longer simply whether Hormuz is open. It is who now emerges as the more effective dealmaker in one of the world’s most critical trade routes.