The Hamas-led terrorist attacks in southern Israel on Oct. 7, 2023 sparked a war that rattled the entire Middle East. One front involved the Israeli-Lebanese border, called the “Blue Line.” From civilian sites in Lebanon, the terrorist group Hezbollah struck Israel with an unprovoked barrage of missiles, rockets and drones.
In response, ground troops of the Israeli Defense Forces overran the Blue Line. They began rooting out Hezbollah militants, evacuating civilians from Southern Lebanon for their safety, and establishing a security zone in the southern expanse. The zone extended to the Litani River, about 20 miles from the Blue Line. Despite the announcement of ceasefires on Nov. 27, 2024 and April 16 of this year, the combatants kept trading blows, with the Lebanese Armed Forces caught helplessly in the middle.
This is the fourth time Israel has been forced to invade Lebanon to repel terrorist offensives. The previous missions were compelled in 1978, 1982 and 2006. Each time Israel deployed troops to the neighboring state, the United Nations called the act an “occupation,” a situation when the armed forces of one state seize effective control over territory in another state. The current security zone in Lebanon presumably counts as occupation number four.
Many non-lawyers view an occupation as a crime. But it is merely a factual scenario that triggers certain legal responsibilities. When an army takes effective control over captured territory, it must: (a) maintain public order in the area; (b) protect the safety of the affected civilians; and (c) respect the domestic laws. In this case, because the IDF has evacuated nearly all civilians from the security zone, there are few left to protect.
Another common assumption about Israel’s occupation of Lebanon is that it violates Lebanese sovereignty. It does not. Occupation law permits Israel to govern the security zone but prohibits it from annexing the land, thus protecting Lebanon’s rights as the ousted sovereign.
Concerns about Lebanese sovereignty are further alleviated by the “unwilling or unable doctrine,” a legal theory that at least some experts believe earns the status of customary international law. Simply put, the doctrine holds that when a state such as Lebanon is unable or unwilling to stop the cross-border aggressions of a domestic terrorist group like Hezbollah, the army of a victimized state like Israel may enter Lebanon in self-defense.
The greatest threat to Lebanon’s sovereignty is Iran. Iran founded Hezbollah in 1982 and cultivated the anti-Israel militia into a Lebanese “state within a state.” Hezbollah renders Lebanon a failed state and repeatedly exploits its territory to attack Israel. By degrading Hezbollah, the IDF helps restore Lebanese sovereignty.
Notwithstanding the sovereignty issue, the occupation law duty to maintain public order gives the IDF broad discretion to eliminate terrorists and dismantle terrorist infrastructure in the security zone. For example, where Hezbollah illegally commandeers the homes and schools of Southern Lebanon for terrorist purposes, the IDF may destroy the structures.
An occupation has no minimum or maximum geographic size. Israel may capture territory north of the Litani and thereby expand the security zone. Meanwhile, the IDF may freely hit Hezbollah positions beyond the zone.
An occupation typically ends when the war ends. But there is no deadline for the transition. The law permits the IDF to disarm Hezbollah, whether the job takes months or years. Israel decided to withdraw its 1982 occupation after 18 years. By that point, the Israeli public had come to resent the intervention as an unproductive quagmire.
Occupation law does not replace the other laws of war. All parties to the fighting in Lebanon remain obligated to direct their attacks against combatants, not civilians. They must ensure that if an attack risks civilian casualties, they are not excessive in relation to the expected military advantage of the strike. And they must take other precautions, if feasible, to minimize the risk of civilian harm.
When the dust settles, Lebanon and Israel should negotiate a peace treaty or security agreement to prevent future terrorist-initiated wars. One useful measure would be to permit mobile IDF monitoring stations among strategic points in Lebanon to detect potential attacks.
Alternately, the parties may preserve the security zone as a demilitarized zone free of terrorist infiltration. That approach would duplicate the main provision of U.N. Security Council Resolution 1701, adopted after the 2006 war to keep Hezbollah forces away from Israel.
Lebanon never complied with Resolution 1701 because the Lebanese Armed Forces were too weak to impose the arrangement on Hezbollah. However, the new version of the scheme could overcome that problem by letting IDF units participate in the enforcement.
Legally speaking, Lebanon and Israel have been at war since 1948. But the alienated neighbors are not really enemies. They are two societies ruptured by Islamist forces beyond their control. The Lebanese government and 86% of the Lebanese people oppose military conflict with Israel.
On April 14, Lebanon and Israel began direct negotiations for the first time since 1993.
Then further rounds of talks ensued. Both sides would benefit from a breakthrough of mutual recognition, diplomatic dialogue, trade ties and other exchanges. The United States has already encouraged Lebanon to join the 2020 Abraham Accords. The key prerequisite to the desired success is to sideline Hezbollah, the terrorist wedge that keeps warping the Blue Line into a battle line. That would moot the need for any more Israeli incursions on Lebanese soil.
