Iran’s Strikes on Ships in Strait of Hormuz Test Cease-Fire and Threaten Oil Flow

The fragile recovery of oil and gas shipments through the Strait of Hormuz was put in jeopardy on Tuesday after three ships were attacked, a burst of violence that drew retaliation against Iran from Washington.

The United States revoked a sanctions waiver that allowed Iran to sell oil for 60 days starting in late June. The lifting of sanctions on Iran, which had faced heavy financial punishment for decades, had represented a shift that could have helped the country rebuild its economy if made permanent.

A U.S. official said that Iran’s actions in the strait were “wholly unacceptable” to the United States. Oil prices, which were already higher, jumped further after the U.S. move.

One of the ships that was attacked, a Qatari liquefied natural gas carrier called Al Rekayyat, was in waters off the Omani coast, according to the International Maritime Organization, a United Nations agency.

Qatar’s foreign ministry blamed Iran and condemned the strike, calling it an “unacceptable attack on the security & safety of international maritime navigation.”

Tehran has not claimed responsibility for the attacks. There was no immediate public comment from the authorities in Iran, where a dayslong program of funeral ceremonies is underway for Ayatollah Ali Khamenei, the supreme leader who was killed on the first day of the war. Negotiations between Iran and the United States have been paused until after the funeral.

The escalation of tension in the region threatened to interrupt what has been the start of a resumption of energy supplies from the region.

“The incident marks the most significant security event affecting commercial shipping in the strait since the U.S.-Iran cease-fire, reinforcing concerns over regional stability, maritime trade and the reliability of global L.N.G. exports,” Kpler, a maritime data company, said in a statement.

The Joint Maritime Information Center, a multinational organization that assesses threats on high-risk shipping routes, said on Tuesday that the risk of sending ships through the strait was “severe,” up from “substantial” on Monday, with further “hostile action considered likely under current conditions.”

The United Kingdom Maritime Trade Operations, a monitoring center led by Britain’s Royal Navy, said in a notice that a ship off the coast of Oman had caught fire after being struck by an unidentified projectile. The agency said that a second tanker was struck by an unidentified projectile and sustained “structural damage.” A third vessel suffered minor damage after being struck by a drone, the agency said.

No casualties or environmental effects were reported in any of the three attacks, according to the British agency.

Iran has said ships can pass through the strait in its waters, but not on the opposite side near Oman. The middle of the strait, which ships used before the Iran war, is considered dangerous because of the risk of mines laid by Iran’s military.

Ami Daniel, the chief executive of Windward, a maritime data company, said Iran wanted to deter ships from using the Omani channel to travel through the strait and lay the groundwork to charge for passage. “So this is a really well planned path to push ships to sail close to Iran and later on pay them for passage,” he said in a statement.

President Trump was in Turkey for a NATO summit where discussions about the war were expected. He has criticized the alliance’s members for not supporting the United States in the war against Iran.

The strait, normally the conduit for a fifth of the world’s oil, was effectively blockaded by Tehran after the United States and Israel attacked Iran in late February. The U.S. Navy also imposed its own blockade of Iranian ports. Economies around the world were hit by the energy supply crunch and rise in prices that followed.

Traffic around the strait picked up in late June, when the preliminary cease-fire agreement between the United States and Iran went into effect. But traffic fell after a bout of Iranian attacks on ships, which prompted U.S. retaliation against Iranian military infrastructure. On Monday, 36 ships passed through the strait in both directions, according to Kpler. Before the war, more than 100 ships a day routinely passed through the strait.

Just three of the ships that transited on Monday took the Omani route, through which the U.S. Navy is providing guidance.

Many ships switch off their transponders before navigating the strait, making it hard to identify their precise routes and giving an incomplete view of traffic volumes. Kpler, a maritime data company, said that the Qatari ship that was hit was last seen in the Arabian Sea on June 18 before it turned off its location transponder.

The price of Brent crude oil, the global benchmark, rose nearly 3 percent when prices settled on Tuesday, to $74.16 a barrel, but then promptly jumped higher, to about $76, after the U.S. sanctions waiver was revoked. As energy exports from the Persian Gulf have recovered, however tentatively, the price of oil has fallen back to near prewar levels. The price of Brent had spiked as high as $118 a barrel during the worst of the fighting.

The effects of the energy shock linger, especially in products derived from oil. The average price of a gallon of gasoline in the United States was $3.79 on Tuesday, according to the AAA motor club, about 27 percent higher than before the war.

Alan Rappeport and Eric Schmitt contributed reporting from Washington, Qasim Nauman from Seoul and Aruni Soni from New York.