Israel and Lebanese Hezbollah: Conflict and Escalation

A day after Hamas (a U.S.-designated foreign terrorist organization, or FTO) led October 7, 2023, attacks against Israel that began their ongoing war, Lebanese Hezbollah (another FTO) started shooting rockets and missiles across Lebanon’s border into Israel in a show of solidarity with Hamas. Subsequently, Hezbollah and Israel repeatedly exchanged fire across the border, and some 60,000 Israeli and 95,000 Lebanese residents evacuated the border area, with displacement in Israel at least partly due to concerns about a possible October 7-style attack from Hezbollah. Iran has long considered Hezbollah its most capable partner in its “axis of resistance” versus Israel. Debate persists about the degree to which Hezbollah acts independently or as Iran’s proxy. After weeks of escalation, Israel landed major blows against Hezbollah’s leadership and capabilities in September 2024, and launched ground operations in October while stepping up its aerial campaign. Hezbollah continues to fire missiles into Israel. Since October 2023, over 2,500 people from Lebanon and more than 70 from Israel have reportedly been killed. Lebanon now faces a humanitarian crisis on top of existing political and economic fragility. To date, the conflict has reportedly displaced 1.3 million people, with some fleeing to neighboring countries. Escalation of Conflict In July and August 2024, attacks by both sides escalated. A rocket attributed to Hezbollah killed young people in the Golan Heights, Israel killed Hezbollah commander Fuad Shukr in response, and the two sides engaged in a major exchange of fire. On September 16, Israel’s cabinet added a goal of returning evacuated Israelis to its official war objectives. A series of ensuing operations claimed by or attributed to Israel took a heavy toll on Hezbollah leadership (and some Lebanese civilians) and highlighted Israeli intelligence and military capabilities. These included the explosion of hundreds of electronic devices apparently used by Hezbollah members, and Israeli airstrikes on hundreds of Hezbollah leadership and military targets. Then, on September 27, Israeli airstrikes in Beirut targeted Hezbollah’s headquarters, killing its Secretary-General Hassan Nasrallah and other senior leaders. Nasrallah had led Hezbollah for 32 years, and had become one of the most prominent leaders in the Middle East. His death raises questions about Hezbollah succession and capabilities and possible responses by Iran, Hezbollah, or other armed groups. Israel killed a potential successor to Nasrallah, Hashem Safieddine, in an October 4 strike. In early October, Israel’s military said it began “limited, localized, and targeted ground raids” into southern Lebanon against Hezbollah, with air and artillery support. An unnamed Israeli official reportedly said that Israel did not intend to occupy southern Lebanon, but sought to create a “security perimeter” for Lebanese or UN forces and facilitate the return home of Israeli evacuees. While supporting the dismantling of Hezbollah “attack

infrastructure,” U.S. officials have reportedly urged Israel to avoid a major ground invasion, and warned that—as with previous Israeli operations in Lebanon in 1982 and 2006— the conflict’s scope and lethal impact could spiral. Israel has reportedly bombarded many Hezbollah-linked targets throughout Lebanon and in Syria, and has called for the evacuation of numerous communities in southern Lebanon (including some north of the Litani River). Hezbollah has continued to fire missiles into Israel, including an attack targeting one of Israeli Prime Minister Benjamin Netanyahu’s residences. Amid reports from the UN Interim Force in Lebanon (UNIFIL) of Israeli fire inflicting some injuries and damages on its troops and facilities, President Joe Biden and officials from several other countries pressed Israel to avoid endangering UNIFIL positions. Israel has called on UNIFIL forces to relocate. Israel-Hezbollah: Selected Historical Events

1982- 1985

Israel’s 1982 invasion of Lebanon elicits some resistance amid Lebanon’s ongoing civil war. Elements from Lebanon’s Shia community—including some responsible for fatal attacks on U.S. and French installations—establish Hezbollah with help from Iran.

1985 Israeli military withdraws from central Lebanon, but maintains a zone of control in predominantly Shia- populated southern Lebanon with a Lebanese partner force. Hezbollah leads resistance to this zone.

1992- 1994

Hezbollah bombings of Israel’s embassy (1992) and a Jewish community center (1994) in Argentina kill 29 and 85 people, respectively.

1996 Hezbollah attacks on Israel and Israeli forces trigger the 17-day Israeli “Operation Grapes of Wrath,” which kills more than 200 Lebanese.

2000 Israel withdraws from southern Lebanon, leading Hezbollah to claim victory. Hezbollah maintains that Israel still occupies Lebanese territory in disputed parts of the tri-border (Israel-Lebanon-Syria) area.

2006 Israel and Hezbollah engage in a 34-day war after a fatal Hezbollah attack and hostage-taking on an Israeli military position. In the war, some 160 Israelis and 1,200 Lebanese are killed. After the war, UN Security Council Resolution (UNSCR) 1701 calls for all non- Lebanese army forces to withdraw north of the Litani River; Hezbollah does not comply and starts to rearm.

2011- Present

Hezbollah helps Iran defend regime of Bashar al Asad in the Syrian civil war. Territorial links from Iran to Lebanon through Iraq and Syria facilitate greater Iranian weapons supply (including precision-guided missiles) to Hezbollah, provoking regular Israeli military strikes in Syria starting around 2012 to prevent or delay these transfers.

Implications for Key Actors Officials in Israel appear to be seeking to seriously degrade Hezbollah’s command structure, morale, and military

Israel and Lebanese Hezbollah: Conflict and Escalation

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capabilities, and to prevent resupply efforts from Iran. They seem to have judged that risks from Israeli military action, including a ground war or retaliatory strikes from Hezbollah and/or Iran, are preferable to a status quo that left Israeli evacuees displaced and Hezbollah expanding its arsenal. Questions persist about which outcomes Israel seeks to or can deliver via military means—such as greater superiority or deterrence against Hezbollah and other regional adversaries, durable diplomatic arrangements for the Israel-Lebanon border area, or a de-linking of this conflict from the war in Gaza. As it battles Israeli ground forces in southern Lebanon, Hezbollah evidently retains some capacity to threaten strategic sites or population centers in Israel with missiles and drones. It also may rely upon a reportedly extensive tunnel network and guided anti-tank missiles. Reports suggest that Israel may have destroyed around half of Hezbollah’s rocket and missile arsenal (see Figure 1). The group has reportedly lost hundreds of fighters and most of its senior leaders in Israeli operations that indicate the group may have been infiltrated by Israeli intelligence. Around October 8, Hezbollah leadership expressed openness to a ceasefire in Lebanon without referring to Gaza. This apparent departure from previous Hezbollah statements has fueled speculation about a possible delinking of the two conflicts. Figure 1. Hezbollah’s Rocket and Missile Arsenal

Source: Center for Strategic and International Studies, March 2024. Iran carried out a ballistic missile attack against Israel on October 1 in retaliation for the killing of Nasrallah (and of Iranian and Hamas figures). Some damage was reported, though no Israeli fatalities, and Israel reportedly plans to respond. Iranian leaders apparently face a challenge of how to support their partners in ongoing operations against Israel and other adversaries without initiating a broader war that could involve the United States and prove destabilizing to the regime. A weakening of Hezbollah, long considered to be Iran’s closest and most powerful partner force, could affect Iran’s decisions regarding efforts to increase deterrence by making changes to its nuclear program. U.S. Policy and Possible Issues for Congress President Biden has pledged continued support for Israel’s right to defend itself against Hezbollah and other Iranian- supported terrorist groups, while enhancing U.S. military posture in the region. On October 8, a State Department spokesperson expressed support for Israeli incursions in Lebanon “to degrade Hizballah’s infrastructure so ultimately we can get a diplomatic resolution that allows [UNSCR] 1701 to finally be fully implemented.”

Diplomacy and U.S. support for Lebanese and UN forces. U.S. diplomats continue, as they have for over a year, to seek a ceasefire and “formula that brings an end to this conflict once and for all,” as the U.S. envoy stated in October 2024, though he conceded that “the situation has escalated out of control.” U.S.-French diplomatic proposals from earlier in 2024 reportedly envisioned the Lebanese Armed Forces (LAF, which Congress has supported for many years with $100 million or more annually) and UNIFIL (to which the United States contributed nearly $170 million from FY2024 funds) patrolling any Lebanese area from which Hezbollah withdraws. Lebanon’s caretaker prime minister indicated a willingness to have the LAF assume this role, though questions may remain about its ability to do so. Israel has reportedly demanded the right to conduct counter-Hezbollah air and ground operations in Lebanon as part of any diplomatic arrangement. Possible U.S. efforts to modify UNIFIL’s mandate or other aspects of UNSCR 1701 could face challenges, given the possible consequences such changes might have for regional security and Lebanese stability. U.S.-Israel security cooperation and arms sales. For more than 50 years, the United States has been the main external source of support for Israel’s self-defense, with Congress enacting regular and supplemental appropriations (over $12.6 billion in FY2024) and designating Israel as a major non-NATO ally. Since the outbreak of conflict in October 2023, some Members of Congress have differed with one another and the Administration on the nature and timing of arms exports to Israel, with some Members advocating greater scrutiny or conditions, and others calling for the Administration to expedite Israeli requests. Direct U.S. military involvement and protection of U.S. citizens. Various scenarios could lead to situations in which U.S. forces in the region authorized to assist with Israel’s defense might become involved in conflict with Hezbollah or Iran. The United States and Israel do not have a formal defense treaty. Congress might debate authorization of the use of military force, and whether U.S. actions to assist Israel’s defense serve U.S. interests and comply with U.S. and international law. U.S. officials say they have evacuated at least 1,000 Americans from Lebanon via air, and have urged the departure of tens of thousands of U.S. citizens that apparently remain. Factors potentially influencing decisions on whether or not to evacuate could include cost, safety conditions, or personal preferences. Humanitarian assistance for Lebanon. In early October, the State Department announced nearly $157 million in U.S. humanitarian assistance for displaced persons and refugees in Lebanon or fleeing to Syria. Lebanese domestic politics. A stalemate since 2022 between Hezbollah, its political partners, and their rivals has blocked the election of a new president. U.S. leaders may seek to support efforts—perhaps via diplomatic pressure and sanctions (as at least two U.S. lawmakers have proposed)—to break this stalemate in light of Hezbollah’s possible weakening. Some foreign officials reportedly warn that such efforts could be unrealistic or fuel instability.

Jim Zanotti, Specialist in Middle Eastern Affairs Clayton Thomas, Specialist in Middle Eastern Affairs

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Israel and Lebanese Hezbollah: Conflict and Escalation

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