Iran weighs its next move as its closest ally takes a hit in Lebanon

Israel’s audacious assassination of Hezbollah’s leader on Friday has rattled the group, delivering its most severe blow since its founding. This has led its Iranian backers to warn that Israel has entered a dangerous phase of the conflict by altering the rules of engagement.

As Tehran watches its most prized non-state ally take a beating, questions are mounting about how it may respond.

The Jewish state significantly escalated its yearlong conflict with the group after expanding its Gaza war objectives on September 17 to include its northern front with Hezbollah. The following day, thousands of pagers used by its members exploded simultaneously, with walkie-talkies targeted the day after that. Israel then began an air assault that killed several Hezbollah commanders and led to the highest number of casualties in Lebanon in almost two decades.

And on Friday, Israel struck what it said was Hezbollah’s headquarters in the southern suburbs of Beirut, killing its leader Hassan Nasrallah.

The Israeli military has claimed that the group’s chain of command “has been almost completely dismantled” after it killed a series of what it says are top officials in the organization this week.

“Hezbollah has taken the biggest blow to its military infrastructure since its inception. In addition to losing weapon depots and facilities, the group has lost most of its senior commanders, and its communications network is broken,” said Hanin Ghaddar, a senior fellow at the Washington Institute and author of “Hezbollahland.”

Despite its losses however, the group still retains skilled commanders and many of its most powerful assets, including precision-guided missiles and long-range missiles that could inflict significant damage to Israel’s military and civilian infrastructure, said Ghaddar. Most of those missiles haven’t been deployed yet.

Since Israel stepped up its campaign, Hezbollah’s military performance “has proven that it was able to absorb that shock and was able to bounce back and it has been striking hard at northern Israel for days now,” said Amal Saad, Hezbollah expert and lecturer in politics and international relations at Cardiff University in Wales.

On Wednesday, Israel intercepted a ballistic missile fired by Hezbollah near Tel Aviv, an unprecedented attack that reached deep into the country’s commercial heartland. Hezbollah said it targeted the headquarters of Israel’s intelligence agency.

While Nasrallah’s killing is unlikely to disrupt the operational continuity of the movement it is “obviously a massive, massive demoralization amongst its ranks and supporters and absolute terror which will temporarily paralyze ordinary people” within the movement, said Saad.

“That doesn’t mean the organization is paralyzed,” she added. “Hezbollah is an organization that was built to absorb these types of shocks… it’s built to be resilient and outlast individual leaders.”

Few contenders for Hezbollah’s leadership can match Nasrallah’s popularity, said Ghaddar, as he is closely associated with the group’s “golden days,” including the end of Israel’s occupation of southern Lebanon in 2000 and the 2006 Israel-Lebanon war, both of which were viewed as major victories for the Lebanese group.

If the group’s leadership is truly dismantled and coordination between Iran and Hezbollah is disrupted, it could prompt Iran’s Islamic Revolutionary Guard Corps (IRGC) to take the lead, according to Ghaddar.

“They (Iran) will have to find a way to do it themselves. But it’s not an easy option as they will (become) targets, and they don’t understand Lebanon.”

Ahead of the attempt on Nasrallah’s life, Iran’s official line was that Hezbollah is capable of defending itself, even as Supreme Leader Ayatollah Ali Khamenei acknowledged on Wednesday that Israel’s killing of the group’s leaders was “definitely a loss.”

Following Friday’s airstrike however, Iran’s embassy in Lebanon indicated that Tehran’s calculations might now be shifting.

“There is no doubt that this reprehensible crime and reckless behavior represent a serious escalation that changes the rules of the game, and that its perpetrator will be punished and disciplined appropriately,” the embassy said on X.

Iran’s rationale for avoiding involvement in the conflict may no longer hold, said Trita Parsi, executive vice president of the Washington DC-based Quincy Institute.

“If it becomes clear (to Iran) that Hezbollah actually cannot defend itself following the bombing in Beirut, particularly if Nasrallah himself was killed, then the Iranian justification for staying out of the war has collapsed,” he said. “At that point, Iran’s credibility with the rest of its partners in the Axis (of regional militant groups) will risk collapsing if Tehran does not react.”

Iran is likely “horrified by the effectiveness and efficiency” of Israel’s attacks but despite the targeting of Hezbollah’s top leadership, Tehran may still believe the group can defend itself and dictate the terms of an eventual ceasefire, which would help the group recover, according to  Farzin Nadimi, a senior fellow at the Washington Institute.

Tehran is most probably already helping Hezbollah rebuild its military command structure and providing tactical and operational advice to its leadership, he said. However, if the group nears collapse, it could “prompt a more assertive Iranian intervention,” potentially in the form of missile and drone strikes, as seen in April when Iran blamed Israel for attacking its diplomatic building in Damascus. Nadimi added that while a larger attack is unlikely, it’s not entirely out of the question.

Saad, the Hezbollah expert from Cardiff University, said an intervention by Iran would likely drag the United States into the war, noting that Tehran was “the weakest link” in the conflict.

“It’s the only member of the Axis that is an actual state. All the others are non-state or quasi-state actors. So, Iran has the most to lose if it participates,” she said.

“(Iran) is a conventional armed force, it would probably not fare anywhere near as well as Hezbollah would in a war because it’s a completely different military infrastructure,” Saad noted. “Hezbollah knows its terrain and adversary better than anyone else.”

Since its inception 40 years ago, the Lebanese militant group has been the crown jewel of Tehran’s so-called Axis of Resistance, a group of mostly Shiite, Iran-allied Islamist militias spanning Iraq, Syria, Lebanon, Gaza and Yemen that gives Iran strategic depth against its adversaries.

As a non-Arab, Shiite state, Iran sees itself as “strategically lonely” in the Middle East and therefore sees Shiites in the Sunni-dominated region “as the closest thing it has to natural allies,” Parsi said..

“From Tehran’s perspective, Hezbollah is central to the Axis because of its capabilities and discipline, its geographical placement, and its ideological and political proximity to Iran’s Islamic Republic,” Parsi added. “The destruction of Hezbollah is not in the cards in my assessment, but if it were to occur, that would be an existential blow to the Axis.”

The group is essential to “maintain a strong military component on the northern borders of Israel and keep Israel off-balance,” said Nadimi from the Washington Institute.

“It will be important to maintain Hezbollah as a viable and resilient actor and ally,” he said. “Iran has designed Hezbollah with resiliency in mind and believes they can take a lot more beating before Iran feels compelled to intervene directly.”

But Iran also has domestic considerations. The escalation between Hezbollah and Israel comes at a delicate time for Iran’s new reformist president, who campaigned on improving foreign relations to lift Tehran out of the isolation that has crippled its economy.

Just this week, President Masoud Pezeshkian said at the United Nations that his country is ready to engage with the West on its disputed nuclear program. He has named as his Vice President Javad Zarif, the seasoned, US-educated diplomat who became the face of Iran’s 2015 nuclear agreement with world powers, abandoned by the administration of former US President Donald Trump in 2018.

Parsi, from the Quincy Institute, said the Hamas attacks on Israel on October 7 and the subsequent escalation with Hezbollah “were very badly timed” for Tehran, since they “risked prematurely bringing forward a confrontation between Iran, Hezbollah and Israel at a time that is much more strategically suitable for Israel than the Axis.”

At home, Pezeshkian must navigate between his reformist constituency, which favors detente with the West, and hardline elements within the regime that want a show of force against Israel.

On Monday, the day nearly 500 Lebanese were killed in Israeli airstrikes, Pezeshkian stated in New York that Iran was ready to “lay down arms if Israel does the same.” The remark sparked intense backlash from hardliners at home for appearing weak in front of the enemy, according to reports. His statement, along with his offer to reconcile with the West in his speech to the UN General Assembly the following day, also drew criticism in some Lebanese media.

Given the “profound unhappiness of much of the Iranian public” with the regime, Pezeshkian’s priority is national reconciliation, said Parsi.

Still, if Hezbollah is seriously degraded, “Tehran may face a situation in which it will conclude that war is at its doorstep whether it chooses it or not and that it is, as a result, better off responding before Hezbollah is further weakened,” he said.

Asked this week by CNN’s Christiane Amanpour if Iran would consider intervening in the Israel-Hezbollah conflict, Vice President Zarif said Tehran was wary of falling into “Israel’s trap,” which he said was aimed at expanding the hostilities by dragging other parties into it, including the US.

He said that both Iran and Hezbollah had exercised restraint in the face of Israeli attacks, “but now the Israelis are crossing the line, in my view, and there is every prospect of the war getting more difficult to contain.” Hezbollah was capable of defending itself, he added, but it was incumbent on the international community to step in before the situation gets “out of hand.”

Iran has yet to carry out the revenge it promised Israel after the assassination of Hamas’ political leader Ismail Haniyeh in Tehran in July.

This week however, Foreign Minister Abbas Araghchi warned that his country would not remain “indifferent” if a full-scale war between Israel and Hezbollah erupted in Lebanon.

“We stand with the people of Lebanon with all means,” he said at a news conference in New York ahead of a UN Security Council meeting.