The United Nations should finally enforce its own resolutions demanding a Hezbollah withdrawal to the Litani River.

In a significant escalation, Hezbollah pummeled northern Israel last week with more than 200 rockets in the terror group’s largest single-day attack since the start of the war in Gaza. The barrage came a day after the Israel Defense Forces killed Taleb Sami Abdullah, a senior Hezbollah commander, in Southern Lebanon.

Israel and the Iran-backed terrorist organization have traded almost daily blows for months, but the frequency and seriousness of these attacks have escalated in recent weeks. If the United Nations Interim Force in Lebanon (UNIFIL) does not execute its mandated mission by stopping Hezbollah attacks on Israel and ensuring the group withdraws north of the Litani River, the steadily intensifying violence on Israel’s northern border could become a full-scale war with massive loss of life.

Since Hamas’s Oct. 7 terrorist attacks, Israel has avoided a major war with Hezbollah for several reasons. They include an Israeli desire to avoid simultaneous large-scale military operations in Gaza and Lebanon, concerns about Hezbollah’s formidable arsenal and Israel’s insufficient preparedness to deal with it, as well as pressure from the Biden administration.

Hezbollah, for its part, has attempted to launch just enough attacks on Israel to show solidarity with Hamas and raise the costs on Israel for its continued operations in Gaza, while avoiding a massive Israeli retaliation that would bring to Lebanon the level of destruction seen in Gaza. Iran, Hezbollah’s terror patron, has been eager for its proxies to harry Israel from all directions but does not want to see the decimation of Hezbollah, which Tehran needs as a deterrent against an Israeli attack on Iran’s nuclear program.

But these delicate dynamics and balances resist indefinite management and might be about to spin out of control with serious consequences for the Lebanese and Israeli people as well as regional security.

How Did We Get to This Point?

Since Israel pulled out of southern Lebanon in 2000, Hezbollah has dramatically expanded its military capabilities with the help of Tehran. In 2010, then-U.S. Defense Secretary Robert Gates stated, “We are now at the point where Hezbollah has far more rockets and missiles than most governments in the world.”

Now, thanks largely to Iran’s support and Israeli reluctance to act more aggressively after the 2006 war, Hezbollah’s arsenal closely resembles that of a mid-size European army, with thousands of drones and mortars and at least 150,000 rockets and missiles. In 2006, Hezbollah fired about 4,000 of its estimated 15,000 rockets and missiles at Israel in a month, but by 2024 the group’s stockpile had grown tenfold.

Over the past eight months, even as Israel has been battling Hamas in Gaza, Hezbollah has conducted more than 1,000 attacks against the Jewish state and launched over 4,000 munitions from Lebanon and Syria into northern Israel, according to the Institute for National Security Studies.

To make matters worse, at least 60,000 Israelis from dozens of communities have fled their homes in the north. Israel, roughly the size of New Jersey, can ill afford to permit its enemies to effectively shrink its borders. Israelis must be able to return to their homes and the government must be able to protect them.

A poll last week in Israel found that more than 60% of Israelis support a decisive attack on Hezbollah. The IDF has deployed multiple brigades along the northern border, where Israeli troops have been conducting exercises.

IDF Chief of Staff Herzi Halevi said last week that a decision on whether to launch a large-scale attack could come soon. The Israeli officer in charge of forces in the north said his forces were ready. The pressure on the Netanyahu government to restore security and deterrence in Israel’s north will only grow.

If that major war comes, the human costs—especially in Lebanon but also in Israel—could be extraordinary. Hezbollah could launch thousands of missiles, rockets, drones and mortars each day for many days. This bombardment likely would overwhelm some Israeli air defenses, impose extraordinary damage on Israel and require the Jewish state to respond with devastating air strikes in Lebanon that could dwarf those undertaken in Gaza in recent months.

Despite Israeli efforts to protect the innocent in such an operation, civilian casualties in Lebanon could be massive, depending on several factors. That’s primarily because Hezbollah has long intertwined its positions and weapon stockpiles with the civilian population.

The success of Hamas’s “human shields” strategy in Gaza likely has motivated Hezbollah to double down on this strategy, which invites and wields civilian deaths as a tool to demonize and isolate Israel and bring its military retaliation to a premature end.

What’s to Be Done?

UNIFIL has roughly 10,000 troops stationed in southern Lebanon. Under U.N. Security Council Resolution 1701, passed in 2006, UNIFIL must ensure, among other things, that the area between Lebanon’s Litani River and the so-called Blue Line (the de facto border between Israel and Lebanon, roughly 30 km south of the river) is “free of any armed personnel, assets and weapons other than those of the government of Lebanon and of UNIFIL.”

The U.N. resolution also authorizes UNIFIL to “take all necessary action in areas of deployment of its forces and as it deems within its capabilities, to ensure that its area of operations is not utilized for hostile activities of any kind.”

Unfortunately, UNIFIL has utterly failed to fulfill this mandate.

U.S. Ambassador to the United Nations Linda Thomas-Greenfield has noted that UNIFIL was “unable to access a range of troubling sites across the Blue Line,” such as rocket launch sites and tunnels that Hezbollah uses to facilitate operations. But UNIFIL freedom of movement south of the Litani River would not be a panacea. Hezbollah has brazenly launched some of its attacks from positions right next to UNIFIL positions, according to the IDF. Clearly, Hezbollah is not particularly concerned about UNIFIL doing its job.

Denizens of the American and European diplomatic cocktail circuit often like to trumpet the value of international organizations and diplomacy in preventing war. Well, now is their moment in Lebanon.

If that major war comes in Lebanon, expect widespread international outrage to be directed at Israel because of the war’s extraordinary humanitarian consequences, which could far surpass what we have seen in Gaza. But here’s the point: If only a fraction of that prospective energy devoted to outrage towards Israel for defending itself could be channeled now into getting UNIFIL to do its job, the war could be avoided altogether.

U.N. Secretary-General António Guterres recently warned that the exchanges of fire between Hezbollah and Israel “could trigger a broader conflict with devastating consequences for the region.” He could not be more correct.

The question is what the secretary-general, the United Nations, its members and UNIFIL are willing to do to avoid such a war. Time may be running out. Those who have followed the United Nations and UNIFIL will not hold their breath that anything will change. That’s why Israeli forces are wise to prepare for full-scale war.

Bradley Bowman is senior director of the Center on Military Political Power (CMPP) at the Foundation for Defense of Democracies (FDD).

Cameron McMillan conducts research on the U.S. military and the Middle East at the Center on Military and Political Power at the Foundation for Defense of Democracies.