Michael Knights is the Jill and Jay Bernstein Fellow of The Washington Institute, specializing in the military and security affairs of Iraq, Iran, and the Persian Gulf states. He is a co-founder of the Militia Spotlight platform, which offers in-depth analysis of developments related to the Iranian-backed militias in Iraq and Syria.
The United States must underscore the risks that such action would incur and incentivize Tehran to rein in its proxies and partners.
As Israel conducts its war against Hamas in Gaza, a major challenge for the United States will be preventing escalation via the participation of Hezbollah, pro-Iran Iraqi militias in Syria or Iraq, the Houthis in Yemen, and perhaps even Iran. Such a regionalization of the war could have catastrophic consequences for the security of Israel and other U.S. partners, for regional stability, and for American interests in the Middle East and beyond.
Accordingly, Washington should proactively try to shape the calculus of these actors by making clear, through words and deeds, that their participation in the conflict would elicit a strong U.S. response. The Biden administration has made a good start in this regard, signaling from the first day of the crisis that the dispatch of U.S. military assets toward the East Mediterranean was intended “to respond to any contingencies and minimize the risk of a wider spread conflict,” adding that the United States would be “deeply concerned about Hezbollah making the wrong decision and choosing to open a second front...” President Biden pointedly advised any states thinking of broadening the war: “Don’t.”
The U.S. admonition is bound to be tested. Lebanese Hezbollah has been probing Israel’s response threshold daily during the past week in a series of incidents along the border. These have included mortar and rocket fire, the launch of an antitank guided missile at vehicles, and perhaps cyber activities to cause false alerts in Israel’s rocket and drone early warning system. Reports have also emerged of Hezbollah fighters as well as Syrian and Iraqi militias being deployed to the Syrian Golan Heights. Mortar rounds have been fired from Syria to the Israeli side of the border. And in a recent parade, the Houthis in Yemen displayed a medium-range missile capable of reaching Israel.
To deter Hezbollah, Iran, and their proxies and partners from expanding the war, the United States needs to underscore the risks they would incur by doing so, and incentivize Tehran to rein in the members of its so-called axis of resistance.
Deterring Hezbollah and Iran
Hezbollah has more than 150,000 rockets, mortars, and missiles that could cause great damage to Israel’s population centers and critical infrastructure. The group’s entry into the war would be a profoundly destabilizing development, which makes deterring it a top priority—as reflected by the Biden administration’s clear messaging on the issue, backed by U.S. military deployments. So far, both Iran and Hezbollah seem intent—at least for now—on limiting the risks of major or unintended escalation that could harm their vital interests. Having perhaps succeeded in disrupting Saudi-Israel normalization (and perhaps the emergence of a U.S.-Saudi military alliance), and having drawn Israel into a destructive new Gaza war, they may not want to overplay their hand. Alternatively, they may be encouraged by success and visions of a triumphant “decisive battle” with Israel to do so.
Several events could alter Hezbollah or Iranian calculations. These include an Israeli military setback in Gaza, an accidental or incremental escalation that generates pressure on Hezbollah or Iran to respond, or a perceived diminution in U.S. or European support for Israel. This suggests that deterrent messaging to Hezbollah and Iran and the nature of U.S. support to Israel will need to be constantly adjusted. To this end, the United States should:
Direct aircraft from the USS Gerald R. Ford Carrier Strike Group (CSG), now in the East Mediterranean, to rehearse strike missions and conduct standoff reconnaissance flights off the coast of Lebanon, with news crews reporting from the carrier’s flight deck.
Quietly signal that U.S. F-35 stealth fighters are operating in the vicinity of Lebanese airspace.
Direct the destroyers and cruisers of the Ford CSG to rehearse joint procedures with Israel’s strategic missile defenses—which are not currently engaged—to send a deterrent message to Hezbollah and Iran.
Deploy heavy bombers to the Gulf region (including B-2 stealth bombers—which would be a first) to remind Tehran that its critical infrastructure—including its oil industry—could be struck if Hezbollah or Iran were to enter the war.
Announce that the USS Dwight D. Eisenhower CSG—which will be leaving for the Mediterranean in the coming days—will visit the Arabian Sea in the course of its deployment.
Although Iran had in the past become accustomed to the presence of carrier strike groups and the dispatch of bomber task forces to the Gulf region, the intensity of the current crisis and the strong, impassioned engagement of President Biden suggest that Iran may be more responsive this time.
Finally, Washington should build on its October 12 decision todeny Tehran access to a $6 billion fund created for the purchase of humanitarian supplies following the recent repatriation of five American hostages held by Iran. It should indicate that if Tehran fails to prevent the participation of Hezbollah and other proxies and partners in the Gaza war, the United States will likewise deny Iran access to an additional $10 billion in frozen funds for the purchase of humanitarian goods now held in Oman—consisting of the proceeds of Iranian gas and electricity sales to Iraq.
Deterring Proxies of Hezbollah and Iran
Hezbollah and Iran might also want to have their proxies and partners—namely, Syria-based militias, Iraqi Shia militias, and Yemen’s Houthis—open additional fronts with Israel and thereby complicate its military calculus. Israel would certainly face significant challenges striking targets in Iraq and Yemen, especially while engaged in operations in Gaza and along its northern border. This is where quiet U.S. messaging to Yemen’s Houthis, Iraqi militias, the Assad regime in Syria, and Iran may bolster Israel’s warnings. Media reports noting U.S. intelligence support for Israeli preparations to respond to a potential Houthi strike by hitting their missile and drone forces or leadership targets might help deter the Yemen-based group. And beyond the threat of a forceful U.S. military response to attacks on American personnel and interests in Syria and Iraq, the most useful way to keep Iraqi militias out of a war with Israel involves threats by the U.S. Treasury Department to prioritize and expedite the blacklisting of banks associated with such militias for abuses of the U.S. dollar.
Michael Eisenstadt is the Kahn Fellow and director of the Military and Security Studies Program at The Washington Institute.