Here’s how Hezbollah will likely respond to Israel’s assassination of Saleh Al-Arouri

Since Hezbollah’s guns began their unprovoked fire against Israel on October 8, 2023, Lebanon has found itself an unwitting battlefield in the war between Israel and the Gaza Strip’s Palestinian terrorist factions. Lebanon, whose territory is both the headquarters of Hezbollah—Iran’s most powerful extension and vanguard of its regional expansionism—and hub of coordination and planning for the Resistance Axis’ anti-Israel operations, couldn’t have expected total immunity. On January 2, Israel eliminated senior Hamas official Saleh Al-Arouri—one of the lynchpins of this coordination effort—in a precision strike in the heart of Hezbollah-controlled south Beirut. The strike also killed two other commanders in Hamas’ Izzeldine Al-Qassam Brigades, Azzam Al-Aqra and Samir Fundi, and four other Hamas fighters. This attack will pin Hezbollah between its obligations to the Resistance Axis and its need to navigate Lebanese political and social dynamics; the latter of which it is also a full participant in.

From 2017 until his assassination, Arouri served as the deputy chairman of Hamas’ political bureau. This deceptively humble title conceals Arouri’s significance. He founded and directed the West Bank branch of Hamas’ Qassam Brigades, was a central coordinating figure of the Resistance Axis’ efforts to “unify the fronts” against Israel, and has been eulogized by Hamas as one of the “architects of Al-Aqsa Flood”—all of which made Arouri a prime target for Israel and an invaluable asset and ally to Hezbollah.

So, when leaks from an Israeli cabinet meeting in August 2023 suggested the Israel Defense Forces (IDF) would resume targeted killings of senior militants in response to the then-ongoing uptick in terror attacks, everyone—including Arouri himself—understood he was marked for liquidation. Consequently, Arouri’s ally, Secretary-General Hassan Nasrallah—whose group, Hezbollah, had formed a protective cocoon around Arouri in Beirut—took to the air on January 3 to threaten Israel against “any assassination on Lebanese territory targeting a Lebanese, Palestinian, Iranian or Syrian,” noting that such measures “[would] be met with a strong reaction.” Nasrallah stressed that Hezbollah “could not remain silent or absorb” such an action because the group’s passivity threatened to “reopen Lebanon again to assassinations.” He also stated that Hezbollah would “not accept any change to the existing rules of engagement” and that “the Israelis must understand this.”

Soon after Arouri’s assassination, Hezbollah issued a statement echoing Nasrallah’s August 2023 address, calling the Israeli strike “a crime” and part of a “policy of liquidation of all who planned, executed, or supported the heroic Al-Aqsa Flood Operation.” Hezbollah further claimed that Israel’s strike was a “dangerous aggression against Lebanon… and development in the war between the [Israeli] enemy and the Axis of Resistance,” which “Hezbollah cannot allow to pass without a response and punishment.”

Nasrallah, in his speech commemorating the deaths of Islamic Revolutionary Guard Corps (IRGC) Quds Force Commander Qasem Soleimani and Kataeb Hezbollah Secretary-General Abu Mahdi al-Muhandis, briefly echoed a variation on that theme, restating his position made in December 2023 that “the battlefield will speak.”

But Nasrallah is notorious for having a much noisier bark than bite; just how loudly he will allow Hezbollah’s guns to roar over Arouri remains in question. Whatever the group may deem the proper response to his assassination in an ideal world, it is currently constrained by Lebanon’s realities: namely, economic freefall and abandonment by its traditional financiers amidst yet another interminable round of political deadlock. Hezbollah is hyper-cognizant of the importance of popular support to its longevity and durability and risks unnecessarily compromising that support—including among its supporters—were it to embark on some military adventure of whatever size against Israel. Doing so would invite untold destruction upon Lebanon, which would compound the country’s ongoing political and economic woes all the more so if it did so to avenge a commander of a Palestinian terrorist organization who was killed in the context of a foreign war.

Since Lebanon began to unravel in 2019, Hezbollah has been acutely cognizant of this Lebanese constraint and how this chafes against its obligations as a constituent organization (and most power member) of the Resistance Axis. Until October 7, 2023, Hezbollah found various methods of navigating this tension between its “resistance” duties and survival, but walking this tightrope became increasingly untenable after Al-Aqsa Flood. The group, therefore, opened fire at Israel along the entire border with Lebanon the next day. Hezbollah’s barrage was at a level not seen since the 2006 war between the two adversaries, and was meant to demonstrate its continued viability as a “resistance” organization. Hezbollah, after all, derives its durability from popular support, which, in turn, is partially dependent on the group’s perceived ability and readiness to confront Israel at any time.

But Hezbollah’s brinksmanship was, by its own admission, a highly calculated risk, and its newfound daring was dependent upon two factors: the first, per Nasrallah, was Israel’s preoccupation with fighting the war in Gaza. “Had just one of our operations during the past month [since October 7, 2023] occurred [before], the enemy wouldn’t have tolerated it, but they do today,” he said on November 3, 2023.

The second factor fueling Hezbollah’s boldness was the knowledge that the Joe Biden administration has pressured Israel to not open up a second front against the group in Lebanon.

With these factors in place and with the knowledge that they would act as a limitation on any Israeli retaliation, Hezbollah allowed itself to escalate along the border. But even this has been relatively limited, aimed largely at harassing Israel, disrupting civilian life, dividing Israeli forces along two fronts, and increasing the war’s burden on the Israeli economy—all in the hopes of slowing Israel’s advance in Gaza so that a premature ceasefire can be imposed before the Resistance Axis forces in the coastal enclave are defeated, allowing the latter to survive and rebuild to fight again in the future. 

What Hezbollah has not been seeking, however, is opening a full-scale war with Israel. Given that Hezbollah’s circumstances after Arouri’s killing remain the same as before his death, that desire is unlikely to have changed. This makes the organization’s promised response—assuming it hasn’t happened already—fairly predictable.

Hezbollah is unlikely to declare an all-out war against Israel, even over someone as critical to the Resistance Axis’ operations as Saleh Al-Arouri. Instead, as it did after Israel killed IRGC Quds Force General Razi Mousavi on December 25, 2023, the group will likely temporarily escalate the intensity of its unceasing attacks on northern Israel—perhaps for a longer duration while trying harder to draw Israeli blood because the attack occurred in Dahiyeh—before resuming its new, post-October 7, 2023 routine of attacks.

Hezbollah also has other indirect options that it may activate. Throughout the past four years, the group has sidestepped the constraints of Lebanon’s economic collapse on its activities by outsourcing its attacks against Israel to Palestinian organizations—primarily the offshoots of Hamas and Palestinian Islamic Jihad (PIJ) in the West Bank, but also to their Lebanon-based franchises. This has allowed Hezbollah to continue bleeding Israel while maintaining just enough plausible deniability to avoid the full brunt of the consequences. Hezbollah has maintained this approach after October 7, 2023, facilitating rocket attacks and incursions by Hamas and PIJ from Lebanon into Israel. Now that Palestinian terrorist factions have threatened to avenge Arouri “on all fronts,” Hezbollah is likely to once again facilitate the use of Lebanese territory by its Palestinian partners to avenge their fallen commander.

Another indirect option may mimic Hezbollah’s behavior after Israel assassinated its former Secretary-General Abbas al-Musawi in 1992. At the time, the group avoided retaliating across the Lebanon-Israel border and embarked upon a campaign of global terror, targeting Israel’s soft underbelly: Israeli diplomatic missions and diaspora Jewish communities. Hezbollah may opt to do so again or to facilitate such attacks by its Palestinian partners.

David Daoud is a senior fellow at Foundation for Defense of Democracies (FDD) focusing on Hezbollah, Lebanon, and Israel.