This aerial photograph shows boats anchored off Oman's northern Musandam Peninsula near the Strait of Hormuz on June 27, 2026. | AFP via Getty ImagesIf you can think back to the distant days of March 2026, you’ll remember that the US-Iran war was, at one point, primarily a conflict over Iran’s nuclear program, though at times it was also about Iran’s treatment of protesters, threat to Israel, missile program, and support for regional proxies. Key takeawaysThis week’s return to fighting in the Middle East made clear that the US-Iran conflict is now primarily a fight over Iran’s ability to control shipping through the Strait of Hormuz, the world’s most important energy chokepoint. Iranians believe control of the Strait is both a deterrent against future attacks and a potential source of revenue. But there are signs it may be overplaying its hand. Ultimately, the longer the situation in the Strait stays chaotic, the more Iran’s rivals are likely to lose patience, either looking for workarounds or returning to war. At this point, however, it’s now clear that it’s about something entirely different, and something that wasn’t even an issue until this conflict began more than four months ago: Iran’s ability to control shipping through the Strait of Hormuz. Iran’s ability to use cheap drones and missiles to throttle ship traffic through the crucial waterway, through which around a fifth of the world’s oil and gas normally transits, became, during the war, its primary source of leverage against the US. Iran’s new leaders now view de facto control of the Strait as their primary deterrent against future attacks by their enemies — an arguably more effective and flexible deterrent than their nuclear program ever was — as well as a potential source of revenue via tolls and fees. Iranian officials have in recent days variously described the Strait as a “golden weapon” and a “divine blessing.” US Secretary of State Marco Rubio has called it Iran’s “economic nuclear weapon.”This week, however, as violence flared again in the region, there were some indications that Iran might be overestimating the power of that weapon and its ability to coerce and deter its enemies. A return to war in the GulfThis week, Iranian leaders showed how far they’re willing to go to protect their “divine blessing,” attacking three ships transiting the Strait with missiles. The ships were traveling through a corridor close to the coast of Oman, under recommendation from the UN’s International Maritime Organization, and had not coordinated with Iranian authorities. This led to the biggest exchange of fire between the two countries since an interim ceasefire agreement in June, with the US bombing more than 80 targets in Iran and the Iranians launching missiles at US targets in Kuwait and Bahrain. The US also reimposed sanctions on Iranian oil sales, while President Donald Trump declared the ceasefire between the two countries to be over. The letter of the dispute comes down to a vaguely worded clause in the Memorandum of Understanding (MOU) between the two countries on June 17. The MOU commits Iran to take steps to restore shipping through the Strait and work with Oman, with which it shares the Strait, to determine future arrangements for administering it. US officials interpreted this as restoring the free navigation through the strait that existed before the war. The Iranians, however, interpret it as giving them control over which ships can cross. This rather wide ambiguity over the control of a very narrow body of water made it easier for both sides to sign the deal, but it’s now led to a new phase of the conflict. After the deal was completed, oil shipments through the Strait returned to around half of their prewar levels, but much of it was on ships traveling at night with their identification systems turned off, escorted by the US Navy.That was an unacceptable situation for Iran, whose leaders have signaled they believe they have created a new status quo that gives them a say over who comes and goes in the Strait. The increasing number of ships traveling the Oman route under US protection was a threat to that status quo. Add in the fact that Tehran appears to believe that Trump is reluctant to return to full-scale war, and they calculated that this week’s attacks were a risk worth taking. “Because they believe that the US is deterred from resuming full-scale hostilities, there is scope for pushing the envelope, for pushing their luck and seeing how much they can extract in the Strait,” said Gregory Brew, an Iran and energy analyst at Eurasia Group. This may be a miscalculation. A weapon, but not an all-powerful oneIran’s Hormuz deterrent might be more effective against a more normal politician than Donald Trump. The Iran war is deeply unpopular, and Trump’s Republicans can ill afford high gas prices heading into this year’s midterm elections. But Trump, generally speaking, appears to value his own idiosyncratic political projects — including the conflict with Iran — more than his party’s political prospects. But Trump aside, the ability to close Hormuz may also simply not be as powerful a weapon of mass disruption as many thought it would be. Crude oil prices went as high as $126 per barrel during the war, but usually hovered closer to $100 — well short of the $200 many experts were predicting at the outset of the war. That’s due to a number of factors, including non-Mideast producers like the US increasing production and the fact that the world’s largest importer, China, proved able to suddenly slash those imports far more than anyone realized was possible, leaving more oil for everyone else. And thanks to the wider adoption of electric vehicles and renewable energy sources, oil is simply not as central to the global economy as it once was. This isn’t to say that the crisis isn’t having an economic impact — it’s driving a slow-moving food crisis throughout much of the developing world — but it’s not creating 1970s-type gas lines or even COVID-type supply chain disruptions. “The closure of the Strait of Hormuz was always understood to be this massively destabilizing black swan event,” Brew said. “And it turns out to have been more manageable.”While continued flare-ups in the fighting have driven spikes in oil prices throughout the crisis — including this week — markets have also been quick to settle in the periods of calm that followed. One week after the signing of the MOU, prices were back at pre-war levels. Even during this week’s fighting, oil jumped to only around $80 before receding as the fighting died down. Energy markets appear to be pricing in the expectation that any return to war won’t last long. Iran’s leaders can probably be confident that Trump isn’t inclined to risk large numbers of US casualties by committing ground troops, embarking on a costly regime-change operation, or even returning to the level of airstrikes that we saw at the height of Operation Epic Fury. But they may on the other hand, the cost to the United States of periodic “mowing the grass” strikes is relatively low. The US has also been striking Iranian bridges for the first time since April. This attack on civilian infrastructure rather than military targets suggests Trump’s tolerance for escalation may be higher than the Iranians anticipated. Has Iran bought a diminishing asset? Iran’s moment of maximum leverage may be right now. Oil producers in the region are heavily investing in new pipelines and alternative routes to allow them to eventually bypass the Strait. The more Iran attacks the ships used by its Gulf neighbors, the more it will encourage those investments. The crisis is also driving a surge in demand for electric vehicles in many countries. The more dangerous it stays in the Strait, the more consumers and producers will be incentivized to lessen their dependence on it. In a recent article for Foreign Affairs, the Atlantic Council analyst Nate Swanson argued that there may also be a contradiction between Iran’s twin goals with the Strait: creating a deterrent to future attacks while also extracting maximum economic value from its control of the waterway. Iran has already shown it can shut down shipping at will, as well as attack the energy infrastructure of its neighbors. (It’s worth remembering that any new bypass pipelines built by Saudi Arabia or the United Arab Emirates will still be within range of Iranian missiles and drones.) But the more Tehran tries to squeeze the region economically through tolls, and the more chaos it creates by actually launching attacks on both shipping through the strait and Gulf countries, the more it will seem worth the cost to both the US and countries in the region to go back to war. Some in Tehran may consider this a price worth paying. The recent mass funeral for the late supreme leader Ayatollah Ali Khamenei doubled as a rally and coming-out party for what Iranian leaders hope will be a new regional order that they will help to shape, and control of Hormuz is part of that. But drawing a hard line on this issue will also push back any return to normalcy for a population exhausted by war and economic crisis. Iran has also not yet received the frozen assets held in banks in the Middle East as promised in the deal, and that seems unlikely as long as tankers in the Strait are taking incoming fire. The US and Israel launched this war with what proved to be massive overconfidence in their ability to force a weaker country to bend to their will through sheer dominance in firepower. In this new lower-intensity phase of the conflict, Iran may have similar overconfidence in its ability to coerce its rivals through an advantage in geography. Iranians leaders once believed that their missile forces and regional proxies like Hezbollah could deter foreign attacks and that their nascent nuclear program gave them bargaining leverage with their rivals. Ultimately, that deterrent failed, and Khamenei and many other top Iranian leaders paid with their lives. Their successors believe they’ve now found a more effective deterrent and bargaining chip. If it fails, they can’t say they weren’t warned.