On 27 September 2024, Hassan Nasrallah, the secretary-general of Hezbollah, was assassinated in an Israeli airstrike in Beirut. The strike took place while Hezbollah leaders were meeting at a headquarters located 60 feet (18 m) underground beneath residential buildings in Haret Hreik in the Dahieh suburb. Conducted by the Israeli Air Force using F-15I fighters, the operation involved dropping more than 80 bombs, destroying the underground headquarters as well as nearby buildings. The Israel Defense Forces (IDF) codenamed the operation "New Order" (Hebrew: סדר חדש, romanized: Seder Hadash).

On 28 September 2024, the IDF announced Nasrallah's death; his body was recovered from the rubble the next day. The attack resulted in at least 33 fatalities and more than 195 injuries, including civilians. The fatalities included: Ali Karaki, the commander of Hezbollah's Southern Front; other senior Hezbollah commanders; and Abbas Nilforoushan, deputy commander of the Islamic Revolutionary Guard Corps (IRGC) and commander of the Quds Force in Lebanon.

Earlier in September, some of Hezbollah's most severe setbacks occurred, including the 17 and 18 September explosions of its handheld communication devices and the 20 September assassination of Ibrahim Aqil, commander of the elite Redwan Force. Between 23 September, when Israel began its airstrikes on Lebanon, and 26 September, the day before the headquarters strike, Israeli attacks had killed over 700 people, injured more than 5,000, and displaced hundreds of thousands of Lebanese civilians. On 27 September, Israeli prime minister Benjamin Netanyahu addressed the United Nations (UN), saying Israel was dedicated to peace, but would continue to pursue its ongoing campaign against Hezbollah. The headquarters strike occurred after Netanyahu concluded his speech.

Lebanese prime minister Najib Mikati condemned this and prior Israeli attacks on Lebanon, denouncing the ongoing Israeli attacks as "a war of extermination". On 27 November, a ceasefire agreement between Israel and Lebanon went into effect, although several violations have since occurred.

The day after Hamas's 7 October 2023 attacks on Israel, Hezbollah fired rockets at the Shebaa Farms, claiming solidarity with the "Palestinian people". This quickly escalated into regular cross-border military exchanges with Israel, impacting northern Israel, southern Lebanon and the Golan Heights. Hezbollah condemned the killing of civilians in Gaza, and said it aimed to pressure Israel by forcing it to fight on two fronts. Hezbollah offered an immediate ceasefire should a ceasefire also happen in Gaza. From 8 October 2023 to 20 September 2024, Hezbollah launched 1,900 cross border attacks, and Israel launched 8,300. The fighting killed 52 in Israel (including 27 civilians), 564 in Lebanon (including 133 civilians), and displaced entire communities in Israel and Lebanon, with significant damage to civilian infrastructure.

In July, another senior Hezbollah military leader, Fuad Shukr, was also assassinated in Beirut. On 10 September, the Israeli Defense Minister Yoav Gallant said Israel was shifting its focus from Gaza to the northern border.

On 17 and 18 September, thousands of handheld pagers and walkie-talkies exploded in a coordinated series of attacks. The explosions killed 42 people and injured at least 3,500, including many civilians. An unnamed Hezbollah official told Reuters 1,500 Hezbollah fighters were taken out of action by injuries. Despite Israel initially denying involvement with the attack, it was orchestrated by Israel's intelligence service (Mossad) and military.

In response, Hezbollah, who described the attack as a possible declaration of war by Israel, launched a rocket attack on northern Israel a few days later. On 20 September 2024, tensions further rose after Ibrahim Aqil was killed in an Israeli strike in Beirut, along with other senior commanders from the unit. After advising Lebanese citizens to evacuate, Israel began airstrikes on 23 September.