Villagers in southern Lebanon have been heading north, fearing all-out war. Most schools are closed. Israel has ordered its citizens to vacate 28 towns along the border with Lebanon. The Israeli army has exchanged fire with Hezbollah—Lebanon’s Shia political and paramilitary group—every day since October 7, resulting in casualties on both sides. Iran’s supreme leader, Ayatollah Ali Khamenei, has said, “We must respond to what is happening in Gaza”; its foreign minister, Amir Abdollahian, warned of a preemptive strike by Iran’s allies against Israel.

And yet, 12 days after the Hamas attack on Israel, the man who holds some of the cards and usually sets the tone, Hassan Nasrallah, Hezbollah’s leader, is still silent—no speeches, no interviews. For someone who loves to give fiery addresses to his followers and does so regularly, Nasrallah’s reticence is notable and can mean only one thing.   

Hezbollah is keeping its powder (mostly) dry while Iran weighs its options and their possible outcomes. Israel has called up 300,000 reservists, the United States has sent two carrier strike groups to the Mediterranean, and President Joe Biden headed to the region with one word for Hezbollah: “Don’t.” For Tehran, regime survival trumps all considerations—and it requires the survival of Hezbollah in Lebanon, the Islamic Republic’s most valuable asset and a key line of its defense. Every Israeli strike on Gaza, every mass-casualty event, will factor into the calculation as both Iran and Hezbollah assess their next moves.

[Read: A message from Iran]

Washington has said it has no evidence directly linking Tehran to the Hamas attack, but a long-standing, though not always easy, relationship binds the Palestinian group to the Iranian regime. Tehran supplies weapons and money to Hamas, and Hezbollah is reported to have provided training. Over the past year, the head of Iran’s paramilitary Quds Force, General Esmail Ghaani, worked to coordinate Iran’s proxies, and Nasrallah has spoken often this year of the unification of fronts. The order to initiate the attack may not have come from Tehran, but Hamas could have had a sort of blanket approval for efforts to launch such an operation. Tehran may have little understood what the attack would unleash. Despite Abdollahian’s bombast, the so-called axis of resistance appears somewhat stunned by its own horrifying success, which was in part made possible by Israel’s slow response on the day of the attacks.

“We were expecting to get a smaller number of hostages and return, but the army collapsed in front of us, what were we to do?” was how the Beirut-based Hamas leader Ali Barakeh put it to The Washington Post on Monday.

The unexpectedly high Israeli death toll may be one reason Nasrallah has kept silent—he is hedging, watching to see when and how far the Israeli army will go into Gaza, and whether Hamas will face an existential threat that requires Hezbollah’s response. Even then, Iran would likely prefer to sacrifice Hamas rather than waste Hezbollah, unless Iran itself comes under threat.  

By keeping Israel on edge on its northern border, Hezbollah is in effect already helping Hamas, but doing so within the rules of engagement established after the 2006 Israel-Hezbollah war. Both sides understand that script, although the risk of a miscalculation is great. For now, Israeli officials are making clear that they don’t want a war with Lebanon—and simultaneously threatening to destroy the country if Hezbollah goes too far. Hezbollah has put out stern statements saying that it’s responding to enemy fire while, at the same time, having its spokesperson claim that the “skirmishes” are only a “warning.”

Hezbollah learned a hard lesson in 2006 about intervening in a war to back up Hamas. In early June of that year, Israel carried out the targeted killing of a Palestinian leader, and Hamas kidnapped an Israeli conscript, Gilad Shalit. By June 28, Hamas and Israel were at war, and the Israeli army had entered northern Gaza. The war would last for weeks. On July 12, as a show of support for the Palestinians, Hezbollah carried out a cross-border raid into northern Israel and kidnapped two Israeli soldiers. Three soldiers were killed during the ambush.

The Israeli response to the kidnappings was devastating for Lebanon, involving not only a ground invasion but massive air strikes, which killed an estimated 1,200 civilians; flattened large parts of the capital’s southern suburbs, where Hezbollah operates; and caused extensive damage to civilian infrastructure across the country. On August 27, shortly after a cease-fire was declared, Nasrallah made a startling admission in a television interview. “We did not think, even 1 percent, that the capture [of two Israeli soldiers] would lead to a war at this time and of this magnitude. You ask me, if I had known on July 11 … that the operation would lead to such a war, would I do it? I say no, absolutely not.”

Much has changed since the 2006 war, for all the parties involved. With Iran’s help, Hezbollah’s capabilities have increased considerably in the past 17 years. The group now has an estimated 60,000 fighters and a stockpile of missiles that went from 14,000 to 150,000 and includes precision guided missiles, according to experts. If Israel can level large parts of Beirut or other areas of Lebanon in the event of an escalation, Hezbollah is now also able to inflict devastating damage deep into Israel. This capability will be factored into Israel’s planning for a ground war in Gaza: How far can Israel go before Hezbollah unleashes a barrage of rockets? One possible scenario is that even an escalation would remain scripted, with both sides opting for precision strikes rather than a barrage of fire.

In parallel with Iran’s expansionist agenda, Hezbollah’s role in the region has grown since 2006. A local Lebanese Shia militia and a political party has now become a regional paramilitary group with a presence in Yemen, Iraq, and Syria, much to the dismay of other Arab countries, including Saudi Arabia. Since 2013, Hezbollah has been assisting the regime of Syrian President Bashar al-Assad to brutally put down what had started as a peaceful uprising in 2011. Israel has conducted regular air strikes against Hezbollah and Iranian assets in Syria. Over the weekend, Israel struck the Damascus and Aleppo airports, raising the possibility of a Syrian front against Israel rather than one in Lebanon. Hezbollah would still be involved and play a key role, but Israeli retaliation would target Syria, a country that’s still at war and that has a president who owes his survival to Tehran and will have little say as to whether or how he will participate.

Most concerning for Hezbollah is its domestic and regional standing. In 2006, Nasrallah was seen as an icon who stood up to Israel for 34 days and emerged alive, denying the mighty Israeli army a victory—though at great cost to Lebanon. Israel had wrongly assumed that many Lebanese would blame Hezbollah for attracting Israel’s wrath. But after initial outrage that Hezbollah had dragged the country to war, the Lebanese directed their fury at Israel for destroying Lebanon’s infrastructure and for the high casualty toll. For a few years afterward, according to one poll, Nasrallah was the most popular leader in the Arab world (although he won only 26 percent of the vote).

Today is not 2006, however. Hezbollah has lost its shine in the eyes of much of the Arab world. Lebanon has been exhausted by a three-year economic crisis, and it is still recovering from the massive explosion at the Beirut port in 2020. Many Lebanese assign Hezbollah a portion of the blame for both of these calamities. Over the past two years, Lebanon’s Christian, Druze, and Sunni communities have each had an altercation or a violent clash with Hezbollah. On Friday, Hamas called for demonstrations across the region in support of its cause. Several thousand of Hezbollah’s core supporters answered that call across Lebanon, but the response was overall tepid and performative.

Still, the mood can easily turn, even if not in support of war, toward more vociferous expressions of support for the Palestinians or anger at the United States. In the hours after the al-Ahli hospital was hit in Gaza, several hundred protesters on mopeds drove from the southern suburbs to the U.S. embassy on the northern outskirts of Beirut, setting a nearby building on fire.

Tehran may well have been surprised by the extent of Hamas’s operation, but it is adept at recalibrating. It will capitalize on the global sympathy for Palestinians that the devastating pictures out of Gaza inspire, as well as on the fact that Israeli-Saudi normalization talks are on ice and the U.S. president is being shunned by Arab countries. But despite its bombast and rhetoric, the regime in Iran is not suicidal and will not seek to take a last stand and go down in flames. Whatever Tehran does now, together with Hezbollah, will be carefully calculated to ensure the survival of the regime and a smooth transition for the succession of the 84-year-old Khamenei.

Under pressure at home from an agitated, young population and economic sanctions, surrounded by countries cozying up to his archenemy, Israel, Khamenei has been working to improve Iran’s hand thanks to ties with China and Russia and the use of proxy militias. He also bought some breathing space and legitimacy with the rapprochement with Saudi Arabia in March. He is now using the Palestinian cause to re-burnish his regional credentials.

[Read: Four misconceptions about the war in Gaza]

Diplomacy is only now kicking in, with a sputter. Biden’s meetings with Arab leaders have been canceled in protest at the ongoing Israeli military campaign against Gaza and Washington’s refusal to call for a cease-fire. A political opening may be possible at a much later stage of the conflict, and at that time, Tehran may want a part in regional diplomacy.

In 1990, Iran was still exhausted by the Iran-Iraq war, and its pragmatic president, Hashemi Rafsanjani, wanted his country to be readmitted into the international community. He condemned Iraq’s invasion of Kuwait and reconciled with Saudi Arabia after a break of several years. In an effort to further garner the goodwill of the United States, Rafsanjani pushed Iran’s proxies in Lebanon to release the Western hostages that they had been holding since the mid-’80s. But when the 1991 Arab-Israeli peace conference was held in Madrid, Iran was excluded, in a slight it never forgot. Today’s Iran is much different; its president is no Rafsanjani, but the country again has domestic and economic problems that could drive it to seek inclusion or guarantees.  

If the current outbreak of violence leads to an opening for a wider settlement, Iran seems unlikely to get a seat at the table. But stranger things have happened in the Middle East—and Iran’s proxies will have made sure that Tehran has been heard and its price has been set.

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