JERUSALEM – The sun was rising in the Mediterranean on a recent morning when the crew of an Iranian cargo ship heard an explosion. The ship, the Shahr and Kord, was about 50 miles off the coast of Israel, and from the bridge they saw a cloud of smoke rising from one of the hundreds of containers piled on the deck.
The Iranian state shipping company said the ship was going to Spain and called the explosion an “act of terrorism”.
But the attack on Shahr and Kord this month was just one of the last saved in a long-running secret conflict between Israel and Iran. An Israeli official said the attack was a retaliation for an Iranian attack on an Israeli cargo ship in the month. past.
Since 2019, Israel has been attacking ships carrying Iranian oil and weapons across the eastern Mediterranean and the Red Sea, opening up a new seafront in a regional shadow war that previously took place over land and air.
Iran appears to have responded silently with its own clandestine attacks. The latest occurred 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 the axis of Israel’s efforts to curb Iran’s military influence in the Middle East and prevent Iranian efforts to circumvent American sanctions on its oil industry.
But the spread of the conflict risks escalating what has been a relatively limited eye for an eye, and further complicates the Biden government’s efforts to persuade Iran to reintroduce limits on its nuclear program in exchange for easing sanctions.
“This is a full-fledged cold war that is in danger of heating up with a single mistake,” said Ali Vaez, director of the Iran program at the International Crisis Group, a Brussels-based research organization. “We are still in a staggered spiral that is in danger of getting out of control.”
Since 2019, Israeli commandos have attacked at least 10 ships carrying Iranian cargo, according to an American officer and a former Israeli officer. The actual number of vessels targeted may be more than 20, according to an Iranian Petroleum Ministry official, an adviser to the ministry and an oil trader.
The Israeli attacks were first reported by The Wall Street Journal.
Most of the ships carried fuel from Iran to their ally, Syria, and two carried military equipment, according to an American officer and two senior Israeli officials. An American officer and an Israeli officer said that the Shahr and Kord were carrying military equipment to Syria.
The Israeli government declined to comment.
The extent of Iran’s retaliation is unclear. Most attacks are carried out clandestinely and without public claims of responsibility.
The Israeli ship attacked last month was a freighter, the Helios Ray, which was transporting several thousand German-made cars to China.
As the ship circled the Strait of Hormuz, a narrow passage on the coast of Iran, a motorboat behind it accelerated, whizzing by the side of the freighter. The commands posted 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 opened two holes in the hull.
Several tankers were similarly attacked in the Red Sea last fall and winter, actions that some officials attributed to the Houthis, an Iran-backed rebel movement in Yemen.
Iran has denied involvement in all of these attacks which, like the Israelis, appeared not to have the intention of sinking the ships, but to send a message.
“You attack us here, we will attack you there,” said Gheis Ghoreishi, a political analyst who advised Iran’s Foreign Ministry on Middle East affairs. “Iran and Israel are bringing their secret war into the open waters.”
The long dark war between Israel and Iran has accelerated in recent years. Iran has armed and financed militias across the region, notably in Syria, Iraq, Yemen, Gaza and Lebanon, where it supports Hezbollah, a Shiite militia and political movement that has long been an enemy of Israel.
Israel tried to contain Iran’s power play by launching regular air strikes against Iranian land and air shipments of weapons and other cargo to Syria and Lebanon. These attacks made these routes more risky and diverted at least part of the arms transit 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 cyber attacks, including a failed Iranian attack on an Israeli municipal water system last April and an attack retaliation in an 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 plotting to attack Israeli, American and Emirate targets.
The sum is an undeclared conflict that neither side wants to escalate to frontal combat.
“Neither Israel nor Iran wants to take public responsibility for the attacks, because that would be an act of war with military consequences,” Hossein Dalirian, a military analyst affiliated with Iran’s Islamic Revolutionary Guards Corps, told The New York Times in a discussion. at the Clubhouse on Thursday. “But attacks on ships at this level could not have happened without a state behind them.”
“We are at war, but with the lights off,” he added.
The dynamics complicate the Biden government’s already charged efforts to rebuild the 2015 nuclear deal that imposed limits on Iran’s nuclear enrichment program in exchange for sanctions. President Donald J. Trump withdrew from the deal in 2018, reinstating these sanctions and imposing a series of new ones.
“This increases the political price that the Biden government would have to pay to provide Iranians with any kind of economic relief,” said Vaez. “If Iran is involved in this type of currency exchange with Israel, while putting pressure on the American presence in the region, it makes restoring the agreement much more difficult.”
Analysts say Iran wants to continue to incite Israel and to arm and support its Middle East allies, both to surround Israel with well-armed prosecutors and to give Iran a stronger hand in any future nuclear negotiations.
Israel’s leadership believes the previous nuclear deal was insufficient and would like to eliminate any chance of reviving a similar pact. An Israeli official said the attacks were part of a broader strategy to force Tehran to agree to tougher restrictions on its nuclear ambitions, as well as restrictions on the ballistic missile program and support for regional militias.
That campaign, The Times previously reported, also included an Israeli attack on a major Iranian nuclear facility in July and the assassination of Iran’s top nuclear scientist last November. Israel has not publicly recognized any of the operations.
The Israeli offensive against Iranian maritime transport serves two purposes, analysts and officials said. The first is to prevent Tehran from sending equipment to Lebanon to help Hezbollah build a precision missile program, which Israel considers a strategic threat.
The second is to dry up an important source of oil revenue for Tehran, based on the pressure inflicted by American sanctions. After the United States imposed sanctions on Iran’s fuel industry in late 2018, the Iranian government became more dependent on clandestine transport.
The attacks were carried out by Flotilla 13, an elite Israeli Navy command unit that has been involved in clandestine operations since the early years of the Israeli state, according to the two Israeli officials and the American officer.
Israeli officials said two of the attacked ships were carrying equipment for Hezbollah’s missile program.
One, they said, carried an industrial planetary mixer, a device used to make solid rocket fuel for missiles. The device was supposed to replace an old mixer that was destroyed in an Israeli air strike in Beirut in August 2019, Israeli officials said.
Previous Israeli air strikes against Iranian trains and cargo in Syria have also targeted equipment for the manufacture of guided missiles.
The tankers targeted by Israel were transporting Iranian oil to Syria, in breach of American sanctions and probably worth hundreds of millions of dollars.
Israeli officials said Syria paid Iran cash or provided logistical assistance to Syrian members of Iran’s Quds Force, an arm of the Revolutionary Guard, and Hezbollah.
Syrian President Bashar al-Assad, also under sanctions, urgently needs oil. Iran, with its economy decimated by American sanctions, needs money. Hezbollah has also been hit hard by the severe economic and political crisis in Lebanon and by a cyber attack on its financial system.
The Israeli attacks are therefore “a way to prevent Iran from selling to Syria, obtaining money and giving it to Hezbollah,” said Sima Shine, former head of research at Mossad, the Israeli intelligence agency.
The attacks typically involve limpet mines and sometimes torpedoes, the American official said. They generally target the engines or propellers of ships, an Israeli official said. And their goal is to paralyze, but not sink the ships, American and Israeli officials said.
The attacks escalated in late 2020, when Trump’s term ended. In response, Iran’s Revolutionary Guard began discreetly escorting oil tankers across the Red Sea, before ships from Russia, an Iranian ally, accompanied them from a distance across the Mediterranean, the American official said.
The attack on Shahr and Kord occurred when the Russian escort was far enough away for the Israelis to attack, the official added.
The effectiveness of the Israeli campaign is unclear. Some of the targeted ships were forced to return to Iran without delivering their cargo, the American official said.
Iranians associated with the Iranian Petroleum Ministry said that in all cases the ships suffered minor damage, the crews were not injured and repairs were carried out in a few days.
American 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 is concern among maritime experts that the cost of a maritime war may exceed its benefit.
Although the Israeli Navy can make its presence felt in the Mediterranean and the Red Sea, it is less effective in waters closer to Iran. And that can make Israeli-owned ships more vulnerable to Iranian attacks as they pass the west coast. from Iran en route to Gulf ports, said Shaul Chorev, a retired Israeli admiral who now heads the University of Haifa’s Maritime Policy and Strategy Research Center.
“Israel’s strategic interests in the Persian Gulf and related waterways will undoubtedly grow,” he wrote in a statement, “and the Israeli Navy is unable to protect those interests.”
Patrick Kingsley reported from Jerusalem, Ronen Bergman from Tel Aviv, Farnaz Fassihi from New York and Eric Schmitt from Washington.