JERUSALEM – The sun was rising over the Mediterranean one recent morning when the crew of an Iranian freighter heard an explosion. The ship, the Shahr e Kord, was about 50 miles off the coast of Israel, and from the bridge they saw a plume of smoke rising from one of the hundreds of containers stacked on the deck.
The Iranian state shipping company said the ship was headed for Spain and called the explosion a “terrorist act.”
But the attack on the Shahr e Kord this month was just one of the latest salvoes in a long-running covert conflict between Israel and Iran. An Israeli official said the attack was in retaliation for an Iranian assault on an Israeli cargo ship last month.
Since 2019, Israel has been attacking ships carrying Iranian oil and weapons across the eastern Mediterranean and the Red Seas, opening up a new sea front in a shadow regional war that had previously unfolded by land and air.
Iran appears to have responded quietly with its own clandestine attacks. The latest came on Thursday afternoon, when an Israeli-owned container ship, the Lori, was hit by an Iranian missile in the Arabian Sea, an Israeli official said. No casualties or significant damage were reported.
The Israeli campaign, confirmed by American, Israeli and Iranian officials, has become a lynchpin of Israel’s effort to curb Iran’s military influence in the Middle East and to hamper Iranian efforts to circumvent US sanctions on its oil industry.
But the expansion of the conflict risks an escalation of what has been a tit-for-tat relatively limited, further complicating the Biden administration’s efforts to persuade Iran to reintroduce limits on its nuclear program in exchange for relief. of the sanctions.
“This is a full-blown cold war that risks heating up with a single mistake,” said Ali Vaez, director of the Iran program at International Crisis Group, a Brussels-based research organization. “We are still in a growing spiral that is at risk of spiraling out of control.”
Since 2019, Israeli commandos have attacked at least 10 ships carrying Iranian cargo, according to a US official and a former senior Israeli official. The actual number of target ships may be higher than 20, according to an official at Iran’s Oil Ministry, a ministry adviser and an oil trader.
The Israeli attacks were first reported by The Wall Street Journal.
Most of the ships were carrying fuel from Iran to its ally Syria, and two were carrying military equipment, according to a US official and two senior Israeli officials. A US official and an Israeli official said the Shahr e Kord was transporting military equipment to Syria.
The Israeli government declined to comment.
The extent of Iran’s retaliation is unclear. Most of the attacks are carried out clandestinely and without public claims of responsibility.
The Israeli ship attacked last month was a freighter, the Helios Ray, carrying several thousand German-made cars to China.
As the ship rounded the Strait of Hormuz, a narrow passage off the coast of Iran, a speedboat following it sped up and glided alongside the freighter. The commandos placed two timed explosives on the port side of the ship, one meter above the water, according to a person with knowledge of the subsequent investigation.
Twenty minutes later, the explosives blew two holes in the hull.
Several tankers were similarly attacked in the Red Sea last fall and winter, actions some officials attributed to the Houthis, an Iranian-backed rebel movement in Yemen.
Iran has denied its involvement in all these attacks which, like the Israelis, appeared to be intended not to sink the ships but to send a message.
“If he attacks us here, we will attack him there,” said Gheis Ghoreishi, a political analyst who has advised Iran’s Foreign Ministry on Middle East issues. “Iran and Israel are taking their covert war to the open sea.”
The long-running shadow war between Israel and Iran has accelerated in recent years. Iran has been arming and funding militias throughout the region, especially in Syria, Iraq, Yemen, Gaza and Lebanon, where it supports Hezbollah, a Shiite militia and political movement that is a longtime enemy of Israel.
Israel has tried to counter Iran’s power play by launching regular airstrikes against Iranian ground and air shipments of weapons and other cargoes to Syria and Lebanon. Those attacks have made those routes more risky and have shifted at least part of the arms traffic and conflict to the sea, analysts said.
Israel has also tried to undermine Iran’s nuclear program through assassinations and sabotage on Iranian soil, and both sides are accused of cyberattacks, including a failed Iranian attack on an Israeli municipal water system last April and a retaliatory Israeli attack on a important Iranian port.
Iran’s Quds force was blamed for a bomb that exploded near the Israeli embassy in New Delhi in January. And 15 militants linked to Iran were arrested last month in Ethiopia for conspiring to attack Israeli, American and Emirati targets.
The sum is an undeclared conflict that neither side wants to escalate into head-on combat.
“Neither Israel nor Iran want to publicly take responsibility for the attacks because doing so would be an act of war with military consequences,” Hossein Dalirian, a military analyst affiliated with Iran’s Islamic Revolutionary Guard Corps, told The New York Times in a discussion in the Clubhouse. Thursday. “But attacks on ships at this level could not happen without a state behind it.”
“We are at war but with the lights off,” he added.
The dynamics complicate the Biden administration’s already tense efforts to rebuild the 2015 nuclear deal that imposed limits on Iran’s nuclear enrichment program in exchange for sanctions relief. President Donald J. Trump withdrew from the agreement in 2018, reinstating those sanctions and imposing a number of new ones.
“It raises the political price that the Biden administration would have to pay to provide the Iranians with any kind of economic relief,” Vaez said. “If Iran is involved in this kind of tit-for-tat with Israel, while putting pressure on the American presence in the region, restoring the deal is much more difficult.”
Analysts say Iran wants to continue to pressure Israel and arm and support its Middle Eastern allies, both to surround Israel with well-armed proxies and to give Iran a stronger hand in any future nuclear negotiations.
Israel’s leadership believes that the previous nuclear deal was insufficient and would like to spoil any chance of resurrecting a similar deal. An Israeli official said the attacks were part of a broader strategy to force Tehran to accept tougher and prolonged restrictions on its nuclear ambitions, as well as restrictions on its ballistic missile program and its support for regional militias.
That campaign, The Times previously reported, also included an Israeli attack on a major Iranian nuclear site in July and the assassination of Iran’s top nuclear scientist last November. Israel has not publicly acknowledged either operation.
The Israeli offensive against Iranian shipping has two goals, analysts and officials said. The first is to prevent Tehran from sending teams to Lebanon to help Hezbollah build a precision missile program, which Israel considers a strategic threat.
The second is to dry up a major source of oil revenue for Tehran, taking advantage of the pressure US sanctions have inflicted. After the United States imposed sanctions on Iran’s fuel industry in late 2018, the Iranian government became more reliant on clandestine shipping.
The attacks were carried out by Flotilla 13, an elite command unit of the Israeli Navy that has been involved in clandestine operations since the early years of the Israeli state, according to the two Israeli officials and the American official.
Israeli officials said two of the ships it attacked were carrying equipment for Hezbollah’s missile program.
One, they said, carried an industrial planetary mixer, a device used to produce solid rocket fuel for missiles. The device was intended to replace an older mixer that was destroyed in an Israeli airstrike in Beirut in August 2019, Israeli officials said.
Previous Israeli airstrikes against Iranian convoys and cargoes in Syria also targeted equipment to make guided missiles.
The tankers attacked by Israel were transporting Iranian oil to Syria, in violation of US sanctions and most likely worth hundreds of millions of dollars.
Israeli officials said Syria paid Iran in cash or by providing logistical assistance to Syrian members of Iran’s Quds Force, a branch of the Revolutionary Guard, and Hezbollah.
Syria’s President Bashar al-Assad, also under sanctions, desperately needs oil. Iran, with its economy decimated by US sanctions, needs cash. Hezbollah has also been hit hard by the severe economic and political crisis in Lebanon and a cyberattack on its financial system.
Thus, the Israeli strikes are “a way to prevent Iran from selling Syria and getting money and giving it to Hezbollah,” said Sima Shine, a former head of investigation at Mossad, the Israeli intelligence agency.
The attacks typically include limpet mines and sometimes torpedoes, the US official said. They are usually aimed at ships’ engines or propellers, an Israeli official said. And they intend to paralyze but not sink the ships, US and Israeli officials said.
The attacks escalated towards the end of 2020, as Trump’s term was drawing to a close. In response, Iran’s Revolutionary Guard began discreetly escorting tankers across the Red Sea, before ships from Russia, an Iranian ally, escorted them from a distance across the Mediterranean, the US official said.
The attack on the Shahr e Kord occurred when the Russian escort was far enough away for the Israelis to strike, the official added.
The effectiveness of the Israeli campaign is unclear. Some of the attacked ships were forced to return to Iran without surrendering their cargo, the US official said.
Iranians associated with the Iranian Oil Ministry said that in all cases the ships suffered minor damage, crews were not injured and repairs were carried out within a few days.
US and Israeli officials said there was no connection between the Israeli campaign and a recent oil spill that left tons of tar on the beaches of Israel and Lebanon.
Within Israel, there are concerns among maritime experts that the cost of a maritime war may exceed its benefits.
While the Israeli Navy can make its presence felt in the Mediterranean and Red Sea, it is less effective in waters closer to Iran. And that could make Israeli-owned ships more vulnerable to Iranian attacks as they pass through Iran’s western shores on their way to ports in the Gulf, said Shaul Chorev, a retired Israeli admiral who now runs the Center for Maritime Policy and Strategy Research at the University of Haifa.
“Israeli strategic interests in the Persian Gulf and related waterways will undoubtedly grow,” he wrote in a statement, “and the Israeli Navy does not have the capacity to protect these interests.”
Patrick Kingsley reported from Jerusalem, Ronen Bergman from Tel Aviv, Farnaz Fassihi from New York and Eric Schmitt from Washington.