Explainer: Will Israel carry out a ground invasion of south Lebanon?

Israel airstrikes on southern Lebanon have killed over 636 people since Monday, after Tel Aviv began waging what it code-named Northern Arrows on 23 September. The escalation in tensions comes as a number of pagers and walkie-talkie devices exploded across Lebanon in a series of attacks between 17 and 18 September, killing 42 people, and injuring thousands more.

The incidents were blamed on Israel’s Mossad agency, prompting Hezbollah to interpret the coordinated attacks as a declaration of war. Soon after, on 20 September, Israeli forces killed Ibrahim Aqil, who served as the commander-in-chief- of Hezbollah’s Redwan forces, alongside other senior commanders from the unit.

Since Monday, Israel has struck southern Lebanon, amid other locations, repeatedly. The attacks have triggered the displacement of at least 90,000 into other parts of the country, as well as neighbouring Syria, and Iraq.

Amid the large-scale attacks, occurring in the backdrop of Israel’s war on Gaza, fears of a ground invasion have increased, but what would a ground invasion of Lebanon look like in 2024?

Israel's history of invading Lebanon

Israel has a history of invading Lebanon, with the first incident dating as far back as 1978. The invasion was in response to attacks, carried out by several Palestinian resistance groups, chiefly the Palestinian Liberation Organisation (PLO), who had established themselves in southern Lebanon.

Operation Litani as it was dubbed, resulted in the killing of between 1,100 - 2,000 Lebanese and Palestinians, and entailed air, artillery, and naval bombardment.

Israel’s heavy shelling resulted in the destruction of Lebanese homes and the displacement of hundreds of thousands more. Among Israel’s weapons in southern Lebanon were US-made cluster bombs, in violation of an agreement between the two allies. Israeli forces withdrew later that year, amid the establishment of the UN Interim Force in Lebanon, though confrontations still occurred. Such hostilities resulted in Israel’s second invasion of Lebanon, in 1982.

Israel's invasion sought to destroy the PLO and install a pro-Israel government in Lebanon. Israel not only targeted the PLO but also leftist, Islamic and Syrian groups in the country. Among the worst of its atrocities committed during this invasion was the Sabra and Shatila massacre in Beirut, which killed up to 3,500 people, mostly Lebanese Shias and Palestinians. The war also resulted in the forcible expulsion of the PLO from Lebanon.

Israel carried out its attacks using helicopters, cluster bombs, missile boats, tanks and other armoured vehicles, with ground troops penetrating multiple fronts, leading them to reach the outskirts of Beirut within one week.

Israel gradually withdrew in June 1985, but the residual conflict continued until 2000. The war also saw the emergence of Hezbollah, established with the aid of the Islamic Republic of Iran, as the primary Shia force in the country. It has engaged in frequent fighting with Israel ever since.

In 2006, Israel invaded Lebanon for the third time, in a war that lasted 34 days. The conflict was allegedly aimed at destroying or degrading Hezbollah primarily using air strikes and artillery shelling, but the vast majority of those killed were innocent Lebanese.

Between 1,191 and 1,300 were killed by Israel during the war, with over one million displaced and entire neighbourhoods of Beirut destroyed.

As well as allegations and evidence of Israel deliberately targeting civilians, during the war Israel used cluster bombs and white phosphorus munitions in violation of international law. 

However, one of the major talking points during Israel's brief invasion phase of this war was Hezbollah's success in fighting Israeli forces, which sustained serious casualties as a result of direct ground fighting. 

Will Israel invade Lebanon in 2024?

On Wednesday, Israel’s military chief Lt Gen Herzi Halevi told troops that the ongoing strikes in Lebanon "could pave the way" for the military entering the territory on the ground, meaning an invasion of the country.

"You hear the jets overhead; we have been striking all day. This is both to prepare the ground for your possible entry and to continue degrading Hezbollah," he said, as cited by the BBC.

Halevi told soldiers that they should "not stop" and  "keep striking and hitting them everywhere", in reference to Hezbollah, and claimed that Israel was seeking to "restore peace to the country’s north" amid the strikes.

Additionally, he said that they are seeking to achieve this by "preparing the process of a manoeuvre, which means your military boots... will enter enemy territory", in the army’s most explicit indication that an invasion could be imminent.

“Your entry there with force … will show [Hezbollah] what it is like to meet a professional combat force. You are coming in much stronger than them, much more experienced than them. Go in, destroy the enemy there, and go destroy the infrastructure".

The military’s chief’s comments were published shortly after the Israeli military called up two reserve brigades for "operational missions in the northern arena", in a further sign of a potential invasion.

As threats and strikes continue, the International Organization for Migration said the World Health Organization and the Lebanese Ministry of Public Health are preparing for mass casualty events in Lebanon and maintaining essential services.

Some experts, however, have ruled out a long-term invasion due to Hezbollah’s heavy presence in southern Lebanon.

In an interview with the BBC, the head of the Middle East Center for Studies and Research in Beirut, Brigadier General Hisham Jaber, said that a long-term Israeli presence in Lebanon would be unlikely given the consequences suffered by the Israeli military in 2006.

General Jaber said that he expects Israeli ground operations in Lebanon to be limited to cross-border raids targeting border towns and that each raid that Israel may carry out will not exceed one day in terms of duration.

Israel has carried out raids against border towns throughout its military onslaught in Gaza after Hezbollah vowed it would attack the country until a ceasefire was declared in the Palestinian enclave.

In another interview with the BBC, Israeli analyst Yoav Stern ruled out the possibility that a potential ground incursion would be similar to what happened in 1982. Stern suggested that any invasion would likely be "a slow, cautious and calculated" one, which would include the occupation of towns in southern Lebanon one-by-one, instead of launching a rapid and comprehensive invasion on the main axes.

"It would be similar to what happened in 2006, but at a greater depth inside Lebanese territory, reaching the Litani River," he said.

Stern believes that Israel will primarily aim, through any potential incursion into southern Lebanon, to push Hezbollah fighters north of the Litani River, for two reasons: "to stop the firing of short-range rockets at Israeli towns, and to prevent a recurrence of an attack similar to the October 7 attack in northern Israel".

Meanwhile, Imad Salamey, a professor of political science at the Lebanese American University in Beirut, told Al Jazeera that "the possibility of an Israeli invasion in Lebanon is gaining momentum within the Israeli political and military establishment". 

"Should the Israeli government opt for this strategy, it is likely that the invasion could commence within 72 hours, as Israel may believe that Hezbollah’s control and command structure has been sufficiently weakened, leaving the party vulnerable to a swift strike before it has the chance to regroup," he said on Wednesday.

Though Israel has a history of ground invasions of Lebanon, international and domestic anger and a weakened arsenal could limit an incursion in south Lebanon.

However, the region is still expected to remain in a volatile situation, with the war on Gaza and Israel's escalation of violence in Lebanon yet to show signs of an end.