What is Hezbollah, the militant group poised for war with Israel?

Though Hezbollah denied that it was responsible for the strike, U.S. and Israeli officials attributed the attack to the militant group, and Israel retaliated by striking deep inside Lebanon on Sunday. A retaliatory Israeli airstrike on Tuesday, which killed senior Hezbollah commander Fuad Shukr, hit a densely populated neighborhood on the outskirts of Beirut.

The Beirut strike was followed by the apparent assassination of Hamas leader Ismail Haniyeh early Wednesday in central Tehran, an attack that Iran and Hamas blamed on Israel and which further threatened to send the Middle East into intensified violence.

Here’s what to know about Hezbollah

Hezbollah is a Shiite Muslim militant organization backed by Iran and based in Lebanon. In 1985, during the Lebanese Civil War, the group established a manifesto that established a key goal to be the destruction of Israel, in response to its occupation of southern Lebanon.

Historically a minority group in Lebanon, Shiite Muslims now comprise roughly 32 percent of the country’s population. While Hezbollah once could have been described as simply a proxy of Iran’s Shiite theocracy, the group now has increasing popular support in Lebanon itself, especially as Shiite constituents feel marginalized and unsupported by the state.

Though Hezbollah and its allies lost their majority in Lebanon’s parliament in 2022, the militant group continues to boast significant influence. The United States classifies Hezbollah as a terrorist group and holds the organization responsible for the 1983 bombings of the Beirut U.S. Embassy and Marine barracks.

Over the weekend, Israel bombed a school-turned-shelter in Gaza and killed at least 30 Palestinians, according to local health authorities.

A rocket attack launched from Lebanon on Saturday killed at least a dozen people, all of whom were children and teenagers, in the Israeli-occupied Golan Heights. Israel attributed the attack — the deadliest the country has faced since Oct. 7 — to Hezbollah, though the Lebanese militant organization was quick to deny any involvement.

In response, Israel hit Hezbollah targets deep inside Lebanon on Sunday. On Tuesday, the Israeli military carried out an airstrike in a densely packed neighborhood on the outskirts of Beirut that killed Fuad Shukr, a senior Hezbollah commander allegedly responsible for the Golan Heights attack.

Shukr had been wanted by the United States for purportedly playing “a central role” in the 1983 Beirut bombing that killed roughly 300 American and French soldiers.

Israel shares its northern border with southern Lebanon. Strikes between Hezbollah and Israel have been commonplace for decades, but the recent escalation could push Israel to wage war on two fronts, against Hamas and Lebanon.

On Oct. 8, Hezbollah said it attacked Israeli targets in Shebaa Farms, a disputed area on the border. Israel and the militant group traded fire in the days that followed, with attacks moving deeper and deeper into both Lebanon and Israel in the nearly 10 months that have followed.

As the Jewish state traded fire with the Shiite militant group, peacekeepers from the United Nations said they were working to negotiate with both parties to diffuse a “very dangerous situation.” On Nov. 2, Hezbollah said it had struck 19 targets in Israel concurrently.

During a visit to the northern border last month, Israeli Prime Minister Benjamin Netanyahu said Israel was “prepared for a very intense operation,” and Defense Minister Yoav Gallant threatened to take Lebanon “back to the Stone Age.” Hezbollah maintained that it would not relent until a cease-fire was reached in the Gaza Strip.

In a visit Monday to the Israeli-occupied Golan Heights — the site of Saturday’s deadly strike from Lebanon — Netanyahu said Israel “will not, and cannot, ignore this,” before vowing to retaliate. “Our response will come, and it will be severe.”

International officials have tried to use diplomacy to stop a looming war. United States Defense Secretary Lloyd Austin said Tuesday that Washington will defend Israel in the aftermath of an attack from Hezbollah, though he still hoped for a diplomatic solution.

The Israeli army is battered by almost 10 months of bloody battle against Hamas on its Gaza border. Hezbollah presents a larger, more strategic and better-armed foe than Hamas, with many wary of Israel’s stamina to pursue another full-scale offensive in the north.

A war with Israel would also be costly for Hezbollah and Lebanon, both in terms of the country’s likely casualty count and the possible risk to Hezbollah of losing its political influence in Lebanon.

Lebanon has been bracing for a possible full-blown war since the Saturday strike hit Golan Heights, as Beirut residents stocked up on emergency supplies in case retaliatory strikes from Israel were to hit Israel’s capital. Hezbollah militants threatened to target Haifa and other Israeli cities if Beirut was hit — which happened Tuesday.

The growing conflict could reverberate throughout the Middle East, as Turkish President Recep Tayyip Erdogan hinted that his country could “enter” Israel if the situation called for it.

Air France, Lufthansa and Turkish Airlines were among the air carriers to cancel flights to Beirut this week, and the list of countries with advisories cautioning their citizens against visiting Lebanon continues to grow.

Hamas, the militant group responsible for the Oct. 7 attacks on Israel, took control of the Gaza Strip in 2006 and is committed to eliminating Israel to establish an Arab Palestinian state.

Hezbollah and Hamas have taken opposite stances on the Syrian civil war, with Hezbollah supporting dictator Bashar al-Assad, who practices a branch of Shiite Islam, while Hamas observes Sunni Islam.

However, their strong and shared opposition to Israel’s existence has brought the two groups closer together.

Hezbollah has also trained rebels of the Houthi party, a Shiite Islamist organization that emerged from Yemen in the 1990s, as well as militias in Iraq. Last month, Israel intercepted a missile from Yemen after the Israeli military struck a Houthi-controlled port there, which came in response to a rare Houthi attack on Tel Aviv the day before.

Iran’s Shiite theocracy backs all three groups.

Hamas has denied any involvement from Iran and Hezbollah in planning the Oct. 7 attacks on Israel. Iran has also denied any role in the Hamas attack, though some political science professors say it is likely that Hezbollah and Iran provided Hamas with advice on launching the Oct. 7 invasion.

Hezbollah said its Oct. 8 attacks on the disputed Shebaa Farms area were launched “in solidarity” with Hamas, and at a rally in Beirut, a Hezbollah leader expressed further support. “Our hearts are with you,” the militant said of Hamas. “Our history and guns and our rockets are with you.”