Hezbollah’s Modus Operandi of Combat with Israel: The Unwritten Rules of Engagement

Over the years and through numerous speeches and articles published by the Hezbollah leadership, there is a conceptual framework for its use of military power against Israel. The main components of this framework are “balance of deterrence,” a term used to describe the mutual willingness of two sides to engage in warfare and to face the risks of an armed conflict, and “equations,” which refers to the calculated way each side responds to the other side’s acts. This analysis will present those terms in the context of the pre- and post-October 7 regional landscape surrounding Hamas’ massacre in Israel and the ongoing exchange of fire between Hezbollah and Israel along the border with Lebanon.

The Rules of the Game Pre-October 7, 2023

During the last 18 years since the 2006 Lebanon War with Israel, Hezbollah’s military capabilities were rebuilt with significant Iranian support. The result of this effort is that current estimations of Hezbollah’s massive missile and rocket arsenal stand at over 130,000 weapons with various operational ranges and payloads that can target any point in Israel. Most analysts agree that the main aim of this continuous investment by Tehran was to transform Hezbollah into an Iranian forward operating base meant to deter Israel from attacking Tehran’s nuclear infrastructure.

Nevertheless, over the years—and especially in response to Israel’s ongoing military activities in Syria aimed at severing Iranian supply routes to Lebanon—Hezbollah tried to establish tactical deterrence (as a “balance of deterrence”) to prevent those Israeli attacks. Using his public speeches, Hassan Nasrallah, Hezbollah’s secretary-general, had set the following rules of engagement: any Israeli attack on Hezbollah or Iranian personnel in Syria or Lebanon and any attack on the organization’s infrastructure in Lebanon will be answered militarily. As Nasrallah holds the final word regarding Hezbollah’s use of force, any terror attack initiated by the organization must be approved by him, and therefore would follow the logic he had set.

Since 2006, and especially after Israel started attacking the Iranian supply routes in Syria in a campaign which began in 2014 and is referred to as the “campaign between the wars,” it appeared that Hezbollah chose to use its military force against Israel according to a complex decision matrix—or “equations.” It took into consideration the following factors regarding the Israeli act, before coming up with the “appropriate and proportional” response:

• The nature of the target (military vs. civilian);
• The damage caused (materiel vs. casualties); and
• The geographic location (along the border vs. deep in land).

Taking into consideration Hezbollah’s logic, Israel’s attacks on the organization’s supply routes before October 7 were undertaken outside of Lebanon’s territory, either in Syria or Iraq, and were intentionally constructed to ensure minimal casualties. More than one report indicated that Israel used “warning shots” ahead of hitting the targets it was seeking to allow Hezbollah’s terrorists to flee before being hit. In the handful of operations in which the Israeli attacks did cause casualties, the targets were involved in active terror plots against Israeli territory, as opposed to “routine” military buildup.

Those few incidents with casualties, such as Israel’s targeted killing in January 2015 of Jihad Mughniyeh, the son of the late Hezbollah military commander Imad Mughniyeh, and other Hezbollah and IRGC officers along the Israeli-Syrian border, led Hezbollah to retaliate in a very calculated manner. The organization chose to target an Israeli border patrol along the Israeli-Lebanese border with anti-tank missiles, causing the deaths of two Israeli soldiers.

This cautious pattern of behavior was seen again in 2019, after Israel was blamed for a targeted drone attack on Hezbollah’s technical equipment in Beirut. Once again in retaliation for an Israeli attack that crossed Hezbollah's red line—attacking on Lebanese soil—Hezbollah retaliated according to the “equations” logic choosing a military target and hitting it with pinpoint accuracy without any casualties. Hezbollah’s response was launching high accuracy anti-tank missiles towards two Israeli military targets along the border, without causing casualties.

Both incidents were followed by a few days of high tensions, but shortly thereafter the quiescence along the border was restored. The relatively stable status quo along the Israel-Lebanon border since the 2006 Lebanon War was a result of the mutual understanding of the above-mentioned “equations” and the wish, shared by both sides, to avoid a devastating full-scale war.

The End of the Known “Equations” Reality

Nevertheless, a day after Hamas’ surprise attack against Israel on October 7, Hezbollah joined the fighting in solidarity with Hamas and opened a campaign of daily attacks on targets along the border with Lebanon. By now, three months into the low-intensity war Hezbollah initiated, it appears that the “equations” logic of the past years is becoming less relevant.

The need to keep an even score with Israel in terms of casualties has been abandoned, as by now more than 130 Hezbollah terrorists have been killed in the ongoing clashes. Hezbollah appears to have given up its past efforts to cause similar numbers of casualties in Israel, which has suffered 10% of this number.

At the same time, while Israel has already hit targets deep inside Lebanon, the Saleh Al-Arouri targeted killing in Beirut being the most prominent one, Hezbollah seems to be careful to focus its fire on northern Israel in what reflects its leadership’s understanding that attacking targets in central Israel might push Israel to declare an all-out war against it.

From the Israeli point of view after the Hamas attack in the south, Israeli decision makers and the public alike are unwilling to cope anymore with a reality in which thousands of Hezbollah terrorists are stationed along the border, a stone’s throw distance from Israeli settlements. Hezbollah’s presence in southern Lebanon stands in total defiance to U.N. Security Council Resolution 1701, which ended the 2006 Lebanon War and called for the expulsion of Hezbollah from southern Lebanon.

The Israeli call for “no more acceptable status quo” along its northern border pushed Israel to pursue a military campaign which does not take into consideration the past “equations.” By now, more than 150 Lebanese have been killed (most of them Hezbollah operatives), Shia Muslim villages used as military platforms have suffered huge damage, and tens of thousands of the southern Lebanon population have fled to the north.

It appears that Israel is willing to risk an all-out war with Hezbollah to push the threat it poses away from its border if diplomatic efforts to achieve this goal fail. The question is whether Hezbollah’s leadership understands the change in the Israeli psyche post-October 7, and how far Hezbollah will go in its refusal of any diplomatic effort to implement U.N. Security Council Resolution 1701.

Dror Doron is a senior advisor at United Against Nuclear Iran (UANI) focusing on Hezbollah and Lebanon. He spent nearly two decades as a senior analyst in the Office of Israel’s Prime Minister. Dror is on Twitter @DrorDoron.