Why Tensions Are Rising on Israel’s Border With Lebanon as it Fights Hamas in Gaza

As Israeli forces finish securing southern towns after the Hamas-led incursion and assembles forces on the border with Gaza, attention is also falling on the country’s volatile northern frontier with Lebanon, where the Israeli Army has been engaged in four consecutive days of clashes with armed militants.

Various Palestinian factions in Lebanon have claimed responsibility for attacks this week into Israeli territory, which has prompted retaliatory strikes from Israel. But it is Lebanon’s most powerful militant organization, Hezbollah, the Iran-backed Shiite group committed to the destruction of the Jewish state, that remains the most serious threat to Israel.

With its vast arsenal of rockets and thousands of experienced fighters who gained combat experience in neighboring Syria’s civil war, Hezbollah has long been seen in Israel as a formidable fighting force. Founded in 1985 to fight the Israeli occupation of southern Lebanon, Hezbollah, an ally of Hamas, has grown into a powerful organization whose leader, Hassan Nasrallah, has also transformed the group into an influential political force inside the country.

Israel briefly invaded Lebanon in 2006 after Hezbollah assailants crossed the border and abducted two Israeli soldiers, prompting a war that left parts of the country in ruins. Despite occasional skirmishes in the years since, border tensions have remained relatively contained.

The fighting in recent days is the most serious escalation since the 2006 war.

Israeli forces have also exchanged fire across the border with Syria, where some Hezbollah fighters are based. The clashes, though limited for now, means that Israel’s military could be engaged in fighting on three fronts as it tries to respond to the broadest incursion in 50 years.

Hamas has strengthened ties with Iran and Hezbollah in recent years following a period of colder relations a decade ago, when the two armed groups backed opposing sides in the Syrian civil war. Hamas, a Sunni Muslim group, backed the Sunni militias rebelling against President Bashar al-Assad, whose forces were supported by Shiite fighters from Iran and Hezbollah.

Analysts said they saw signs of that growing partnership in April, when an unusually heavy rocket barrage from Lebanon hit Israel. The Israeli military accused Hamas of orchestrating the strikes with Hezbollah’s blessing.

The partnership has grown such that Hamas on Saturday called on its armed allies in Lebanon to join its assault. Analysts say there is little sign for now that Hezbollah is prepared to launch a war against Israel, and has opted instead for limited strikes from Lebanon that are unlikely to force Israel to escalate its response — but whether that calculation will hold on both sides remains to be seen.