After nine months of brutal fighting in Gaza, Israel and Lebanese Hezbollah appear poised to escalate ongoing hostilities into a broader war. Indeed, both sides are saber-rattling as Israel finalizes heavy operations in Gaza to shift focus to the Lebanon front, with Israel particularly committed to ensuring an enduring defeat of its northern foe. This reality should terrify world leaders who must publicly reject any potential conflict, given the potential for mass displacement on par with the 2015–16 refugee crisis.

Lebanon and Hezbollah have exchanged cross-border fire since October 8—one day after Hamas attacked Israel. Both parties have increased their fiery rhetoric and actions since, expanding the scope and scale of their military operations, targeting increasingly important figures and locations while promising a broader bloody war. Critically, the situation appears to fall outside the normal deterrence structure established after the 2006 war between the two parties.

Israeli leaders are not holding back in public statements, with Israeli defense minister Yoav Gallant repeating prior threats that his country will send Lebanon “back to the stone age” on June 27. This and similar rhetoric from Prime Minister Benjamin Netanyahu highlight Israel’s willingness to invade Lebanon.

Hezbollah’s rhetoric is no different, although it and its sponsor, Iran, appear less inclined to start a full-fledged war. Still, Hezbollah leader Hassan Nasrallah on June 26 claimed that a future fight will have “no rules and no red lines.” This followed the group’s release of drone footage within Israeli airspace that highlights the group’s capacity to strike critical infrastructure—a clear signal that it will Israeli harm done to Lebanon inside Israel.

President Joe Biden dispatched senior officials to Lebanon and Israel to talk the parties down from a full-fledged war, but these efforts are faltering. Hezbollah remains dead-set on conditioning any stop in the fighting on a permanent ceasefire in Gaza—something Netanyahu continues to undermine by speaking out of both sides of its mouth concerning negotiations. In a similar vein, U.S. officials are now doing the same with Hezbollah, with anonymous officials offering assurances the United States will defend Israel in a war.

As such, the situation is precarious. The greatest threat to Israel is Hezbollah—a fact both groups’ leaders understand all too well. Hezbollah must project strength and support for Palestine within its broader resistance ideology to retain legitimacy among its support base. This ideology—for better or worse—drives its thinking, meaning it cannot fall back amid a fight with the Israelis. The United States, meanwhile, claims to support de-escalation but continues to pigeonhole itself into escalatory stances through unconditional support for Israel.

In this scenario, all roads lead to conflict. Israel is very likely to choose force to allow for the return of roughly 96,000 citizens to its northern cities. This says nothing of influential Israelis who still believe their country can and should defeat Hezbollah after two previously embarrassing defeats in Lebanon. Even a flowery reading of the situation, in which Israel tries to induce a relatively informal Gaza ceasefire by ending all major operations after its Rafah invasion in a signal to Hezbollah that it is offering an offramp from the precipice, the odds of such a strategy succeeding are limited. Neither party is likely to be able to restrain fighting to the borderlands either, as much as some have proposed “limited” Israeli operations.

Indeed, that is because an unavoidable escalatory spiral may already exist. Israel will not commit to a complete, permanent ceasefire in Gaza, and Hamas is unlikely to shift from its demands—namely a full Israeli withdrawal and permanent ceasefire. Without an agreement, Hezbollah is unlikely to move on a unilateral ceasefire with Israel. For all the U.S. efforts in achieving positive, peaceful results, the Biden administration has proven incapable of doing what is necessary to achieve an outcome that ends the fighting—largely due to Biden’s apparent belief that Washington must cater to every Israeli demand.

The result is a war between Hezbollah and Israel—one that almost certainly draws in the United States. Israeli Prime Minister Benjamin Netanyahu is a master of U.S. politics, regularly manipulating Washington into supporting his ambitions. When the bombs start falling on Tel Aviv—and they will fall in large numbers as Hezbollah’s 150,000-strong rocket arsenal overruns Israel’s defenses—he will likely opt to publicly embarrass Biden again. This argument will cover familiar rhetorical bases: Biden is not doing enough to support its friend, ally, and lone-democratic Middle East partner.

The U.S. political elite will eat this up, forcing Biden to provide support to the Israelis by directly involving the United States in the war. Rest assured—this will not be the moment Washington says no to Israel after providing blind support to Tel Aviv up to this point. And when U.S. jets start pummeling the Beqaa Valley, the risk of a broader regional war will increase substantially, putting American troops maintaining poorly defended, remote locations in Syria, Iraq, and Jordan at high risk of Iranian or proxy militia attacks.

In this scenario, other regional problems will cascade. Population displacement will have extra-regional implications, compounding ongoing crises in Iraq, Syria, and Lebanon. This will ultimately force an untold number of people to flee for Europe or other regional countries already facing stability issues—including Jordan. Such an outcome would parallel or go beyond the migration crisis of 2015–16, presenting a major problem for Europe amid the war in Ukraine and a rising far-right.

Resources and attention would need to shift to addressing these issues, taking away from the unified but fraying support for Ukraine. Worse, it would distract the United States from its much-needed strategic shift to the Pacific and East Asia, where China is certainly relishing a bogged-down Washington. This says nothing of the negative impact a war in Lebanon would have on U.S. priorities across the Middle East, not limited to efforts to integrate the region politically, economically, and defensively. Finally, with the global aid system stretched to its limits, the impact of broader destabilization on the system would leave most ongoing humanitarian crises worse off—an unacceptable outcome given the lack of funding for even the worst global conflicts in Gaza, Syria, Yemen, Ethiopia, and Sudan.

Ultimately, the risks associated with an Israel-Hezbollah war present a doomsday scenario for American policymakers, but one they can and should avoid. It must be made clear now that the United States will not back an Israeli invasion of Lebanon. Anything short of this approach leaves Washington complicit in a firestorm of its own making.

Alexander Langlois is a foreign policy analyst focused on the Middle East and North Africa. Follow him on X: @langloisajl.

Image: Ran Zisovitch / Shutterstock.com.