Explainer: Why Has Israel Launched A Ground Invasion Of Lebanon?

Israel has invaded southern Lebanon, in what it has called a “limited, localized, and targeted” ground operation against Hezbollah.

Israeli forces on October 1 crossed the border for the first time since the 34-day Israeli-Hezbollah war in 2006.

Hezbollah is both an armed group and political party that controls much of southern Lebanon. It is considered a terrorist organization by the United States, although the European Union has only blacklisted its armed wing.

What Is Israel’s Goal?

The Israeli military has said its aim is to destroy Hezbollah targets along the border. One army division, which usually numbers more than 10,000 soldiers, is involved, it said.

Israel last month made the return of some 60,000 residents of northern Israel displaced by Hezbollah attacks a key war aim. Israel and Hezbollah have exchanged constant cross-border strikes since Israel’s invasion of the Gaza Strip in October 2023.

Michael Horowitz, head of intelligence at the Bahrain-based Le Beck International consultancy, said Israel is trying to dismantle Hezbollah’s infrastructure along the border, including tunnels and observations posts.

“In that sense it is ‘limited,’ as the goal is not to defeat Hezbollah, which would require a much broader invasion of most of Lebanon,” he said.

But it is unclear if Israel’s invasion will be limited in scope.

U.S. officials have noted that Israel initially billed its 1982 invasion of southern Lebanon a “limited” attack, which turned into an 18-year occupation.

Israel has also ordered communities in southern Lebanon to evacuate north of the Awali River, some 60 kilometers from the border, raising concerns of a larger offensive.

Horowitz said Israel risks being “pulled in even deeper” if it tries to create a buffer zone in southern Lebanon. But he said Israeli leaders likely want to avoid being dragged into a protracted war.

“At the same time, if Israeli troops pull back, Hezbollah is likely to come back and launch new attacks against Israel, which would be embarrassing for the Israeli government,” he said.

Can Hezbollah Put Up A Fight?

Hezbollah has suffered major setbacks in recent months. Israel has assassinated most of its leadership, neutralized a significant part of its military arsenal, and disrupted its communications.

While Hezbollah has been weakened, experts said the group should not be written off, given its considerable manpower and military arsenal.

Analysts said Hezbollah fighters have experience in guerrilla warfare and are likely more familiar with the terrain.

Israel thinks Hezbollah is “in a state of chaos, and there's a gap in the command-and-control system,” said Hamidreza Azizi, a fellow at the German Institute for International and Security Affairs. “We can expect initial advances and successes by Israel.”

But Hezbollah, he said, has a “considerable advantage” in ground fighting because of the group’s experience in guerilla warfare and familiarity with local terrain.

Since it was formed in the early 1980s, Hezbollah has grown to become the dominant military power in Lebanon, effectively sidelining the country’s conventional army.

Azizi said the Lebanese Army is “comparatively weak” compared to Hezbollah, which is estimated to have some 40,000 fighters.

The army has only a limited presence in southern Lebanon, where a UN peacekeeping force is deployed. With Hezbollah controlling much of the region, the Lebanese Army is unlikely to play a major role in ground combat with Israeli forces.

The Lebanese army “simply isn't built to defend Lebanon from the [Israeli Defense Forces] and, there is probably a lot of international pressure to move it out of the way,” said Horowitz.

Will Iran Get Involved?

Iran, Hezbollah’s key ally, has been under pressure to respond after Israel’s killing of Hassan Nasrallah, the longtime leader of the organization, in air strikes in Beirut on September 27. Israel’s ground invasion of southern Lebanon is only likely to heap more pressure on Tehran.

But experts said Tehran is unlikely to launch a direct military strike on Israel, a move that could provoke all-out war with its archenemy.

When another Iranian ally, Syrian President Bashar al-Assad, was at risk of being toppled during that country’s civil war, Iran intervened to keep him in power.

But Azizi said Iran is unlikely to deploy proxy forces as well as its own military advisers -- as it did in Syria -- in Lebanon.

The Lebanese government has also blocked Iranian planes from entering the country’s airspace after threats from Israel.

Azizi argued that Iran’s only viable option is to help other members of its so-called axis of resistance -- Tehran’s loose network of proxies and allies – to “mobilize and increase their attacks against Israel.”