May Israel Lawfully Invade Lebanon … Again?

On October 7, 2023, Hamas invaded Israel, killing 1200 Israelis and taking more than 250 hostages, and igniting the Gaza War. The day after, the Lebanon-based, Iranian-funded terrorist group Hezbollah added to the onslaught by firing rockets, artillery shells, and weaponized drones into Israel. Since then, near-daily salvos have killed 25 Israelis and forced over 80,000 others to evacuate their homes. Israel reacted to the Hezbollah attacks with air strikes and artillery fire, following which Hezbollah only intensified its belligerence — to the point of threatening a region-wide war. In response to the hostilities, UN Secretary-General Antonio Guterres issued a statement on June 6^th urging the parties to “recommit to the full implementation of UN Security Council Resolution 1701” (the “2006 Ceasefire Resolution”).[1] Does the 2006 Cease-Fire Resolution restrain either combatant – and in particular does it stop Israel from responding to Hezbollah’s ongoing acts of aggression, especially considering the UN’s failure to carry out its responsibilities under that resolution?

Major acts of terrorism carried out from Lebanon forced Israel to mount a defensive invasion of the country three times: in 1978; 1982; and 2006. These rounds of fighting culminated in ceasefire agreements supplemented by non-binding UN Security Council (UNSC) resolutions,[2] including the 2006 Ceasefire Resolution.[3] Essentially, each UNSC resolution called on Israel to withdraw its forces, requested the terrorists to disarm, asked the Lebanese government to restore order in the embattled territory, and authorized a UN peacekeeping force to support the demilitarization through its monitoring role. On each occasion, Israel withdrew its forces as instructed, but the other parties, including the UN, the architect of the statement, failed to carry out their responsibilities. The terrorists simply rearmed and resumed their attacks. The present Hezbollah offensive continues that tragic trend. At this late date, Secretary-General Guterres cannot naively trust that Hezbollah will start to fulfill its discarded 2006 obligations, nor has he any basis, in law or morality, to expect Israel to tolerate Hezbollah’s ongoing acts of belligerency. Guterres’s June 6^th statement effectively continues to tell Israel, as the UN has done all along in failing to implement the 2006 Resolution, “You’re on your own.”

Every UN member has a right, pursuant to Article 51 of the UN Charter, to use military force in defense against armed attacks.[4] In 2006, when Israel invaded Lebanon to repel Hezbollah attacks, former Secretary-General Kofi Annan minimally acknowledged Israel’s right of self-defense.[5] Article 51 presumably allows Israel’s military to enter Lebanon to counter Hezbollah’s attacks today.

A fourth Israeli ground invasion of Lebanon would probably be bloodier than the first three. Hezbollah has far more fighters, weapons, training, and funding today than it did in 2006.[6] It is also more embedded in residential neighborhoods. The civilian casualty count from such a war could eclipse the death toll in Gaza because Hezbollah would be expected to exploit Lebanon’s larger population to hide behind an even greater number of human shields.

A fourth ground invasion may also spawn harsher, if no more justified, legal consequences than has the Gaza War. International institutions like the UNSC and International Court of Justice (ICJ) all too often act not as independent arbiters of law and fact but in service to the political interests of their member states. With many of those states consistently steeped in anti-Western and anti-Israel animus, the deliberations of the aforesaid institutions are all too often a foregone conclusion.

This anti-Israel coalition invents politicized interpretations of international law, sometimes referred to as “imaginary law,” that hold Israel to uniquely high standards. For example, in 2004 the ICJ acknowledged its lack of jurisdiction over Israel but still issued an advisory (non-binding) ruling that denied Israel’s Article 51 right of self-defense against Palestinian terrorists.[7] The court said Article 51 applies only when the armed attack originates from a foreign “state.” However, the text of Article 51 contains no such limitation, and the UNSC had already recognized the right of the United States to act in self-defense after the 9/11 attack by Al Qaeda, another foreign terrorist group.[8]

Since October 7^th, anti-Israel lawfare has grown more virulent. For example, on December 29^th, a proceeding was commenced in the ICJ to investigate the untenable claim that Israel’s defensive military operation against Hamas in Gaza was a campaign of genocide against the Palestinian people.[9] The ICJ then proceeded to impose provisional measures on Israel based on nothing more than a statement that the claim was “plausible,” a remarkably weak standard. Similarly, on May 20, 2024, the prosecutor of the International Criminal Court (ICC) took a highly controversial action regarding the Gaza War. Even as it solicited arrest warrants for senior leaders of Hamas, based on Hamas’s manifest actions in violation of international humanitarian law, it ignored the unprecedented steps taken by Israel to minimize civilian casualties in the Gaza War, and sought arrest warrants for Israeli senior leaders.[10] In so doing, the ICC ignored the fact that Israel is not subject to ICC jurisdiction. Moreover, the court failed to honor the principle of “complementarity,” which blocks an ICC prosecution where a state such as Israel already has its own judicial process to prosecute war crimes. On May 28^th, three European states known for their hostility toward Israel formally recognized the “State of Palestine,” an aspirational concept that Palestinians commonly regard as a step toward replacing, as opposed to living side-by-side with, Israel.[11]

Another Israeli ground invasion in Lebanon could provoke even more legal blowback. The UNSC may condemn Israel for violating the 2006 Ceasefire Resolution, even though, as noted above, the other parties have not carried out their portions of the resolution and enforcement solely against Israel would deny the Jewish state its right to self defense. A surge in Lebanese civilian casualties may prompt a new meritless charge of genocide against Israel before the ICJ. The ICJ may again deny Israel’s right of self-defense, since Hezbollah is not a “state,” even though Hezbollah dominates the Lebanese government. The ICC prosecutor could again seek indictments of Israeli leaders. Any number of additional nations could recognize the nonexistent State of Palestine. In turn, these legal assaults could accelerate the ongoing upsurge in antisemitic attacks worldwide.

For the above reasons, if Israel sends troops into Lebanon again, the decision would be justified and lawful. However, Israel will probably still be subjected to further opportunistic and questionable legal challenges, as to which Israel could not expect fair treatment from the UNSC, the ICJ, the ICC, or many state governments.

—

[1] Statement attributed to the Spokesperson for the Secretary General on continued exchanges of fire across the Blue Line, June 6, 2026, https://www.un.org/sg/en/content/sg/statement/2024-06-06/statement-attributable-the-spokesperson-for-the-secretary-general-continued-exchanges-of-fire-across-the-blue-line.

[2] A UNSC resolution is considered binding when adopted under Chapter VII of the UN Charter and otherwise indicated by its terms (e.g. an enforcement mechanism) to be binding. The UNSC resolutions on the hostilities in Lebanon did not meet those criteria. More recently, the US State Department clarified that UNSC Resolution 2728 of March 25, 2024, which “demanded” an immediate ceasefire in Gaza, was non-binding. Department of State Press Briefing (March 25, 2024), https://www.state.gov/briefings/department-press-briefing-march-25-2024/.

[3] UNSC Resolution 425 (March 19, 1978), https://unscol.unmissions.org/security-council-resolutions-lebanon; UNSC Resolution 520 (September 17, 1982); https://unscol.unmissions.org/security-council-resolutions-lebanon; and the 2006 Ceasefire Resolution (August 11, 2006), https://peacemaker.un.org/israellebanon-resolution1701.

[4] UN Charter, Art. 51, https://www.un.org/en/about-us/un-charter/full-text#:~:text=Article%2051,maintain%20international%20peace%20and%20security. Article 51 states: “Nothing in the present Charter shall impair the inherent right of individual or collective self-defence if an armed attack occurs against a Member of the United Nations, until the Security Council has taken measures necessary to maintain international peace and security.”

[5] Highlights of the Noon Briefing by Marie Okabe, Deputy Spokesperson for the Secretary-General (July 20, 2006), https://www.un.org/sg/en/content/highlight/2006-07-20.html.

[6] As of October, 2023, experts estimated that Hezbollah had an arsenal of 150,000 rockets and missiles, including long-range precision-guided missiles, anti-aircraft missiles, and anti-tank missiles. In addition, Hezbollah’s fighting force was considered large enough to rival many state armies.

[7] Legal Consequences of the Construction of a Wall in the Occupied Palestinian Territory, Advisory Opinion, 2004 I.C.J. 331 (July 9), paras. 138-142, https://www.icj-cij.org/sites/default/files/case-related/131/131-20040709-ADV-01-00-EN.pdf.

[8] UNSC Resolution 1373 (September 28, 2001), https://undocs.org/Home/Mobile?FinalSymbol=S%2FRES%2F1373(2001)&Language=E&DeviceType=Desktop&LangRequested=False.

[9] Application Instituting Proceedings, Application of the Convention on the Prevention and Punishment of the Crime of Genocide in the Gaza Strip (South Africa v. Israel), International Court of Justice, (December 29, 2023),  https://www.icj-cij.org/case/192/institution-proceedings.

[10] Statement of ICC Prosecutor Karim A.A. Khan KC: Applications for arrest warrants in the situation in the State of Palestine, International Criminal Court, May 24, 2024, https://www.icc-cpi.int/news/statement-icc-prosecutor-karim-aa-khan-kc-applications-arrest-warrants-situation-state.

[11] Associated Press, Spain, Norway and Ireland formally recognize a Palestinian state as EU rift with Israel widens (May 28, 2024), https://apnews.com/article/eu-palestinian-state-spain-israel-gaza-6efe351e53761befc2c539c535bbcc0c.