LONDON — With a U.S. naval blockade taking effect on Monday, oil prices again surging past $100 a barrel and a fragile ceasefire set to expire in nine days, the United States and Iran began the week locked in a standoff after historic peace negotiations in Pakistan collapsed over the weekend.
Washington, Tehran and anxious capitals around the world are not sure how a cascade of urgent questions will resolve: Will the bombing resume when the truce runs out on April 22? What will U.S. Navy operations in the Strait of Hormuz actually entail? And is there any conceivable path to an agreement on an Iranian nuclear program that has now survived not only two decades of international diplomacy seeking to curtail it, but also more than five weeks of the most intensive military assault ever launched against Iranian territory?
Financial markets were not reassured. Oil futures jumped above $103 a barrel as traders reacted to President Donald Trump’s announcement that U.S. warships would block traffic through the Strait of Hormuz. But just how tight a grip the Navy would impose remained unclear.
Trump, in a Truth Social post Sunday, declared a sweeping embargo on “any and all Ships trying to enter, or leave, the Strait of Hormuz.” But U.S. Central Command implied a more limited blockade, saying it would begin stopping all traffic entering and exiting Iranian ports starting at 10 a.m. Eastern time Monday — early evening in the Persian Gulf.
Pakistani officials were determined to keep the sides talking even after their abrupt departure from Islamabad on Sunday. Mediators emphasized that before the collapse, progress had been made on many issues during 21 hours of negotiations led by Vice President JD Vance and Mohammad Bagher Ghalibaf, speaker of Iran’s parliament.
“I don’t think the back-channel communication will stop. I think it will carry on — maybe not as we speak, but I was told it will not cease,” said Maleeha Lodhi, one of Pakistan’s most respected diplomats, who has served as ambassador to the United States, the United Kingdom and the United Nations.
But it was not clear what channels remained open as both American and Iranian leaders quickly returned to their respective maximalist corners.
Trump expressed confidence that Iran’s bombed-out infrastructure and battered economy would still force its hand.
“I think Iran is in very bad shape. I think they’re pretty desperate. Iran will not have a nuclear weapon,” Trump told reporters Sunday. “I don’t care if they come back or not. If they don’t come back, I’m fine.”
Iran, for its part, showed no signs of feeling boxed in.
Commanders of the Islamic Revolutionary Guard Corps described the U.S. naval operations as “piracy” and threatened to target Gulf ports in retaliation. Officials projected the confidence of a regime that, so far, has weathered the worst that the world’s strongest military could deliver.
That perception of survival — despite widespread devastation and the assassinations of many high-level officials — has emboldened hard-liners in Tehran who argue the attacks by U.S. and Israeli warplanes have provided further proof of Iran’s need to develop the deterrent of a potential nuclear threat.
Israeli leaders, who publicly supported but privately regretted Trump’s ceasefire leading to the negotiations, quickly seized on the collapse of the talks to threaten a return to pounding Iran. Gen. Eyal Zamir, the chief of staff of the Israel Defense Forces, instructed the IDF to move to a heightened state of readiness and prepare for a possible resumption of hostilities.
Israeli Prime Minister Benjamin Netanyahu consulted with security officials in Tel Aviv on Sunday on the possibility of resuming the fighting in Iran, according to a person familiar with the matter who spoke on the condition of anonymity because they were not allowed to brief the media. “Israel must be prepared for any development,” this person said.
Lodhi said Pakistan’s diplomats feared the looming blockade could shatter the fragile truce. Trump may intend for the blockade to push Iran back to the negotiating table, but the operation also moves U.S. forces into much closer proximity to Iran.
“It will push the conflict to its most dangerous phase, because it will be up close and personal,” she said. “The Iranians are not going to just rush to the negotiating table since there is a blockade; they are going to respond militarily. They’ve said so.”
Analysts warn that the planned U.S. naval blockade, while well within the capabilities of the forces massed around the Persian Gulf, could face serious military obstacles. The narrow strait forces U.S. warships into a confined channel where Iran’s sea mines, shore-based missiles and swarms of cheap drones could diminish American military advantages.
In 2000, al-Qaeda terrorists managed to attack the USS Cole, a destroyer operating in nearby waters, with a bomb-laden boat, creating a 40-foot hole in the hull and killing 17 sailors.
The logic of the blockade, however, is straightforward: Cutting off Iran’s oil exports would sever access to the hard currency keeping its war economy afloat. So far, Iran’s own blockade of the passage has inflicted more damage to the world economy than to its own, as Iranian tankers have been able to pass the strait more frequently.
“One of the U.S. assumptions going into the war appears to have been that Iran would almost handicap itself by closing the Strait of Hormuz because a lot of its own hydrocarbons transit the same choke point, but that hasn’t happened,” said Sidharth Kaushal, senior research fellow for sea power at the Royal United Services Institute, a British military think tank. “In fact, the Iranians have exported more oil than they did before war, partially because Iranian oil is one of the few cargoes that have been able to safely transit the strait.”
The U.S. is now looking to block Iran and to keep it from establishing permanent control of the strait, Kaushal said.
But the economic blowback could be double-edged: With roughly 7 million barrels of crude and 4 million barrels of refined product already trapped in the Gulf, blocking Iranian oil threatens to push global prices even higher. The strait is also a choke point for other supply-chain commodities, including aluminum, helium and fertilizer.
The blockade is Trump’s latest expression of frustration with Iran’s continued stranglehold on the shipping lane. The president’s public views have vacillated, from his claim in a national address April 1 that the Strait of Hormuz did not matter, to his threat to obliterate Iran’s “entire civilization” if didn’t allow ships to pass, to now his imposition of his own blockade on the already blockaded passage.
Iran said it would strike back hard at the U.S. blockade.
“If Iran’s ports are threatened, NO PORT in the region will be safe,” the Iranian military central command said in a post on X on Monday.
But some experts said the U.S. blockade could effectively push Iran and its oil-dependent allies into a more conciliatory position and was preferable to deploying ground troops to disrupt Iranian exports by occupying key facilities, such as the processing and shipment facilities on Iran’s Kharg Island.
“The blockade always made more sense than seizing Kharg Island,” longtime U.S. diplomat Dennis A. Ross said in a social media post. “It stops Iran’s exports, its revenues, is a counterpoint to their closing the Straits. They may attack Gulf oil facilities but it puts greater pressure on Iran. It also puts great pressure on China to pressure Iran.”
So far, neither side shows signs of budging from core positions, particularly on the issue of Iran’s determination to maintain the nuclear research that it says is intended for legal civilian applications but that Israel and the U.S. insist is destined to provide Tehran with a nuclear weapon.
“The meeting went well, most points were agreed to, but the only point that really mattered, NUCLEAR, was not,” Trump wrote in a post Sunday.
In some ways, Trump now finds himself needing the same thing President Barack Obama needed in 2013, when he and Iranian President Hassan Rouhani started the long negotiations that yielded the 2015 international agreement on Iran’s nuclear program. Trump discarded that agreement during his first presidential term but now finds himself, like Obama, seeking to constrain nuclear ambitions that seem to have proved impervious to sanctions and military force.
In withdrawing from the agreement, Trump sided with Netanyahu’s view that the deal was allowing Iran to make clandestine progress toward a bomb. In its place Trump instituted a program of “maximum pressure,” a slate of punishing sanctions meant to force Iran to give up its enrichment program. In 2025, the U.S. and Israeli launched military strikes that badly degraded Iran’s deeply buried nuclear facilities.
Supporters of the negotiated deal say the military approach has only strengthened Iran’s commitment to obtaining an atomic weapon. Meanwhile, the two military campaigns have left 440 kilograms (about 970 pounds) of highly enriched uranium in tunnels that remain at least partially intact, their exact location unknown even to international inspectors. The stockpile is now harder, not easier, to account for, experts say. Supporters of the 2015 accord contend that Iran’s nuclear program was largely contained and closely monitored when Trump inherited the nuclear file from Obama.
“It’s rare that we’re given, in real time, historical counterfactuals that allow you to compare different methods of dealing with any problem, let alone one as difficult as Iran nuclear program,” said Rob Malley, who was a lead negotiator on the 2015 Iran nuclear deal. “We had diplomacy, we had maximum pressure sanctions, and we had the military. Of the three, I think it’s hard to dispute that the first was the most successful — in fact, was the only one that was sustainable.”
George reported from Islamabad, Pakistan. Mohamad El Chamaa in Beirut and Lior Soroka in Tel Aviv contributed to this report.
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