Iran wants to strike back at Israel but can’t afford a wider war

BEIRUT—Iran and its allies are weighing how to retaliate forcefully for a pair of killings attributed to Israel in Beirut and Tehran without igniting an all-out war none of them want.

Iran can’t afford a war with Israel, which would likely pull in the U.S., just as a new presidential administration takes over in Tehran with problems including a reeling economy. Iranians still hold painful memories of the country’s last extended conflict, an eight-year war with Iraq that decimated a generation, and for decades Tehran has preferred to harry its rivals in the region through a network of foreign militias.

Hezbollah, the Tehran-backed Lebanese group, also has more to lose from escalating its 10-month cross-border battle with Israel into a full-scale war. While Hezbollah has a missile arsenal that could punish Israel severely, its leaders have watched Israel demolish much of Gaza since the Oct. 7 attacks and pick off its leadership—something Israel has vowed to replicate in Lebanon if provoked.

Both suffered major embarrassments recently that analysts say they will feel they must respond to. An Israeli airstrike last week killed one of Hezbollah’s most senior commanders, in a suburb of Beirut. A day later, Hamas political leader Ismail Haniyeh was killed in his room while visiting Tehran for the inauguration of Iran’s new president—an attack that Iran and Hamas blame on Israel, which hasn’t publicly commented on the killing.

Iran and Hezbollah will try to thread the needle between hitting targets of value without doing so much damage that they set off a war. At the same time, both Iran and Hezbollah are penetrated by Israeli intelligence.

“Neither Hezbollah nor Iran wants a comprehensive war now,” said Ali Fadlallah, a Beirut-based independent political scientist familiar with Hezbollah’s thinking. “But at the same time they do not want the Israelis to conclude that their unwillingness to go to war allows them to cross red lines.”

Western officials think Iran and Hezbollah will launch attacks against Israel in the coming days, but hope that a week of frenzied international diplomacy and new military deployments to the region have helped delay and possibly mitigate it.

The U.S. has warned Iran that its recently elected government and its economy could suffer a devastating blow if Tehran were to mount a major attack against Israel, a U.S. official said. Arab diplomats have passed along similar warnings to Iran and have sought to persuade it to climb down.

Israel has signaled its readiness to reply quickly to any strike and even pre-empt one if necessary. The Pentagon ordered additional missile defense-capable cruisers and destroyers, as well as more land-based missile-defense units and another fighter squadron to the Middle East, beefing up assets that already included a carrier strike group and additional warships.

Hezbollah and Arab officials say that Iran and its allies are still assessing whether Israel might use any Iranian-orchestrated attack as an excuse to strike back even harder—and how far the U.S. is willing to go in its support of its ally.

The threat of war has sent a wave of concern through Middle East capitals. In Beirut, residents say they are more worried than they have been in years that current hostilities may spread beyond the country’s south, which has been engulfed in cross-border fighting for 10 months.

In a speech this week, Hezbollah leader Hassan Nasrallah said his group was certain to retaliate, but in its own time.

“Their government, their army, their society, their settlements and their occupiers are all waiting,” Nasrallah said about Israel. The wait, he said, is “part of the punishment.”

“Two attacks broke the rules of engagement and crossed red lines. No country in the world would accept this attack,” said Fadlallah, the Beirut-based political scientist.

At the same time, Hezbollah, which is also a powerful political party, has to appease its own domestic constituency, which is wary of war.

The last time Hezbollah fought a war with Israel, in 2006, many Lebanese rallied around the group. Arabs across the Middle East hailed it as the first nonstate movement to successfully square off with Israel. That won’t happen now, said Sami Nader, director of the Institute of Political Science at Saint Joseph University in Beirut.

“The situation is totally different from the one in 2006. Lebanon has gone through economic collapse, people lost their savings in the banks, the currency lost 98% of its value, unemployment is high,” Nader said. “Hezbollah’s constituency in the south lost their houses once. They don’t want to do it a second time. The timing is not right for a war with Israel.”

While Iran has previously accused Israel of killing nuclear scientists on its soil, the killing of Haniyeh in Tehran was particularly embarrassing, exposing its inability to keep high-value friends secure.

“The location is more important than the target itself. You can’t let your capital be so open to operations,” said Joseph Bahout, director of the Issam Fares Institute for Public Policy and International Affairs at the American University of Beirut. “They will have to reply.”

Yet Iranian leaders face a crisis of legitimacy at home, where pressure builds from citizens fed up with arduous moral strictures and a continuing economic slump.

Newly elected Iranian President Masoud Pezeshkian has promised to address both, calling for improving ties with the West and appointing officials with a record of reducing tensions. A war might put engagement with the West at risk.

As president, Pezeshkian presides over Iran’s Supreme National Security Council, though key military decisions are dominated by the Islamic Revolutionary Guard Corps and taken by the country’s supreme leader, Ayatollah Ali Khamenei.

Iran already faced off directly with Israel once this year. In April, a suspected Israeli airstrike struck an Iranian consulate building in Damascus, Syria, killing 16 people, including eight Revolutionary Guard officers. Iran responded two weeks later by launching more than 300 drones and missiles at Israel, an unprecedented show of force and the first time Tehran targeted Israel directly.

But Iran also telegraphed the attack through diplomatic channels, allowing Israel and a U.S.-led coalition to prepare for the strike and intercept almost all of the incoming missiles and drones. The result headed off significant escalation but was a failure for Iran.

This time, Iran is responding to a different sort of attack in the killing of the Hamas leader on its soil. Iran isn’t expected to respond in kind, as it likely doesn’t have the intelligence or the means to conduct targeted assassinations in Israel akin to the ones that took place in Beirut and Tehran.

One option available to Iran is to go at it alone, as it did in April, but that risks direct Israeli retaliation on Iranian soil. Another option is to orchestrate an attack on Israel through allied militias in Lebanon, Yemen, Iraq and Syria—possibly on several fronts simultaneously, though that increases the complexity.

Yemen’s Houthi militia last month claimed responsibility for a drone strike in Tel Aviv that killed one person and wounded several others, a first for the group and evidence of the growing complications Israel faces.

“Since Oct. 7, Yemen has become a central front against Israel, and the drone in Tel Aviv shortened the distance to Israel,” said Ali al-Mohatwary, a Beirut-based writer affiliated with the Houthi movement. “We will only escalate in support of the Palestinian people.”

War could carry a regional diplomatic cost as well for Tehran, which in recent years has improved relations with its Arab neighbors. Arab officials have also emphasized that the key to achieving peace in the region is for Israel to halt its offensive in Gaza.

Some in Israel, including in Prime Minister Benjamin Netanyahu’s government, have called for an operation in Lebanon to push Hezbollah away from the border and allow displaced families to return to their homes. Polls show that a majority of Israelis support such an operation. A serious attack by Hezbollah could give Israel the pretext to launch the operation.

At the same time, however, there is widespread concern among Israel’s security establishment that opening another front would take an untenable toll on the military, which is stretched thin from fighting in Gaza and relies heavily on fatigued reservists. The Israeli military is also short on munitions, according to a recent court document.

The U.S. is on alert but doesn’t believe Iran could conduct a much larger military campaign on Israel than it did in April, two U.S. officials said.

The U.S. Embassy in Beirut, like other Western diplomatic missions, hasn’t evacuated its staff.

Summer Said, Adam Chamseddine, Laurence Norman, Anat Peled, Dov Lieber, Benoit Faucon and Nancy A. Youssef contributed to this article.

Write to Sune Engel Rasmussen at sune.rasmussen@wsj.com