In a Region on Edge, Israel and Hezbollah Launch Major Attacks on Each Other

Amid fears of an all-out war between Israel and Hezbollah forces in Lebanon, the two sides on Sunday mounted the biggest round of cross-border strikes since the war in Gaza began, with Israel bombing dozens of sites in a pre-emptive attack, and Hezbollah launching hundreds of rockets and drones.

Within hours, both sides appeared to de-escalate, at least temporarily, but signaled that the violence and dangerous tensions could continue. Hezbollah said its operation, vengeance for the Israeli assassination of a senior commander, had “finished for the day,” but left open the possibility of further action. Prime Minister Benjamin Netanyahu of Israel said that “what happened today is not the final word.”

For weeks, Israelis have waited in trepidation for a major attack promised by Hezbollah in retaliation for the airstrike last month in a suburb of Beirut that killed one of its leaders, Fuad Shukr. Iran, which backs both Hezbollah and Hamas, has also vowed retribution for the killing of Ismail Haniyeh, the Hamas political leader, on a visit to Tehran, hours after Mr. Shukr was killed, though it appears to have put that plan on hold.

After the Hamas-led attacks on Oct. 7 that triggered the war in the Gaza Strip, Hezbollah began firing frequently on Israel, prompting widespread Israeli bombardment. Repeated strikes, counter-strikes and threats have forced more than 160,000 people to evacuate on both sides of the border, stoking fears that the conflict would ignite full-scale regional war pitting Israel not only against Hezbollah — a more potent force than Hamas — but also its patron Iran.

Before dawn on Sunday, Israel’s military said it used about 100 warplanes to strike more than 40 Hezbollah launch sites in Lebanon, saying it had acted to prevent a major attack. Lebanon’s Health Ministry said at least three people had been killed and two others hurt, and Israel said a soldier was killed and two others wounded during the Hezbollah barrage.

The Hezbollah leader, Hassan Nasrallah, said in a televised address on Sunday that it had launched 340 rockets at military sites in Israel, which would make it the group’s largest barrage during the Gaza war. Israeli officials said the figure was somewhat lower. Either way, the attack did “very little damage,” the Israeli military said, in part because of its pre-emptive strikes and in part because it had shot down most of the Hezbollah munitions that took flight.

Analysts say both Israel and Hezbollah are unlikely to want to endure a war that would could devastate both countries and kill thousands with little prospect of strategic victory for either side.

Hezbollah wants “to say that we’ve registered a response, and now move on from this phase of anticipation of a wider escalation,” said Mohanad Hage Ali, a Beirut-based fellow at the Carnegie Middle East Center.

But in the run-up to war, “there can be stages,” cautioned Ehud Yaari, an Israel-based fellow at the Washington Institute for Near East Policy, a research group. “You can have escalation that is gradual.”

Mr. Yaari noted, however, that all of the reported Israeli targets in Lebanon were within 30 miles of the border, focused on thwarting the threat from Hezbollah’s rocket and drone arsenal rather than striking its broader infrastructure, suggesting a measure of restraint.

On the other side of the border, Mr. Nasrallah similarly suggested that the current round of escalation might be at an end, and that Hezbollah was willing to consider the reprisals for Mr. Shukr’s death concluded. “If we decide that this initial response isn’t enough and needs completion, that can come later, at another time,” he said. “At the current stage, people can take a breath and relax.”

The United States has sought to prevent a wider regional war, in part by trying to advance a cease-fire between Israel and Hamas in Gaza. But Washington has also steadily deployed two aircraft carrier groups and a guided-missile submarine to the region, both to deter Iran and its allies from attacking Israel, and to aid in responding to such an attack.

Israel’s defense minister, Yoav Gallant, said he had spoken with U.S. Secretary of Defense Lloyd J. Austin III on Sunday to discuss “the importance of avoiding regional escalation.”

The talks on a Gaza cease-fire and the release of hostages resumed as planned on Sunday, after senior Israeli and Hamas officials arrived in Cairo to meet with mediators. Despite a full-bore diplomatic push from the Biden administration, Israel and Hamas remain far apart on critical issues, leading officials to conclude that an immediate breakthrough is unlikely.

Mr. Nasrallah said Hezbollah waited four weeks to retaliate for the killing of Mr. Shukr “to give enough time for the negotiations that were taking place over Gaza,” which appear to have made minimal progress in that time.

While most of Hezbollah’s weapons were fired at targets in northern Israel, some were launched at a military site in central Israel, reflecting the growing range and sophistication of group’s Hezbollah’s arsenal. Israeli and American officials said that those munitions were drones, and that all were shot down.

Mr. Nasrallah identified the target in central Israel as the Glilot military base just outside Tel Aviv, headquarters of Unit 8200, a vaunted signals intelligence branch of the Israeli military, which he said was connected to the strike on Mr. Shukr. The base lies some 70 miles from the Lebanese border.

Four Israeli officials, speaking on condition of anonymity to discuss sensitive operational topics, said they believed Hezbollah had intended to target the headquarters of both Unit 8200 and Mossad, the country’s foreign intelligence service. There was a buildup of intelligence over recent days and into Saturday night, the officials said, providing enough information to identify what was being targeted and when an attack would take place.

Once the visual surveillance detected clear movement of missiles, the officials said, the Israeli military recommended the strike on launchers, weapons stockpiles and other targets in Lebanon. A U.S. official said American drones and aircraft provided some of the surveillance imagery used to target Hezbollah launchers.

Mr. Nasrallah disputed the Israeli claim to have largely defeated the attack, saying that the strike at Glilot was successful, and that none of the rocket launchers Hezbollah intended to use in the barrage were destroyed ahead of time. He did not provide evidence.

Hostilities between Hezbollah and Israel — closely tied to the long-running “shadow war” between Iran and Israel — have heated up dramatically since war between Israel and Hamas began in October. Hezbollah has said it was acting in solidarity with Hamas, and that its attacks on Israel would stop when it ends its offensive in Gaza. Some Israeli officials have suggested that Israel could invade Lebanon to push Hezbollah back from the border.

Mr. Nasrallah said the Hezbollah barrage on Sunday was timed to begin at 5:15 a.m. At around 4:55 a.m., the Israeli military announced that its warplanes were carrying out a surprise series of strikes in an attempt to defeat the Hezbollah attack before it began.

In a video statement, the Israeli military’s chief spokesman, Rear Adm. Daniel Hagari, said Israel “took the initiative to attack in order to remove the threat.”

Little more than half an hour later, air-raid sirens blared across northern Israel as rockets streaked across the border, and Israeli air defenses fired missiles to destroy them. Mr. Nasrallah said the rocket barrage aimed to distract Israel’s defenses to allow attack drones headed for Glilot to slip through.

In a statement after the attack, Mr. Netanyahu vowed to defend the country and create the conditions to allow displaced Israelis to go home. “Whoever harms us, we will harm them,” he told his cabinet.

In Lebanon, some Hezbollah supporters praised the group’s attack, saying Hezbollah had demonstrated its strength while avoiding an escalation that lead to a devastating, full-scale war. But others reacted with disappointment, saying Hezbollah had not gone far enough to avenge the assassination of Mr. Shukr, noting that Mr. Nasrallah had said that if Beirut were struck, the group would hit Tel Aviv.

“If this is the response for Shukr’s death, I think that they will lose a lot of support from the public,” said Mohammed Awada, 52, a taxi driver who lives in Beirut’s southern suburbs, an area of the Lebanese capital where Hezbollah holds sway. “They did not even get close to their promise.”

Reporting was contributed by Ronen Bergman, Hwaida Saad, Gabby Sobelman, Johnatan Reiss, Eric Schmitt, Minho Kim, Vivek Shankar, Yan Zhuang and Vivian Yee.