After months of rising tensions in the Red Sea region, a U.S.-led coalition has launched air and missile strikes on Yemen to prevent further Houthi attacks on cargo ships and to keep shipping lanes open. But military action alone is unlikely to solve the problem, and to sustainably secure freedom of navigation in the Red Sea, the United States may need to move to stop the war in Gaza—the root cause of an unfolding regional conflict that could still be halted. In the long term, none of the region’s complex political crises can be resolved through military action alone.

The U.S. military, along with forces from the United Kingdom and support from Australia, Bahrain, Canada, and the Netherlands, struck targets in Yemen on January 11. In a statement, President Joe Biden said the strikes were intended to secure international trade and protect U.S. forces in the region.

Although the Houthis have taken a beating, and may be in for more in the coming weeks, it’s not clear that the threat to Red Sea shipping can be sustainably ended from the air. The Houthis are likely to keep trying, having vowed not to stop until Israel aborts its offensive in Gaza.

The United States has to respond in some way to the Houthi attacks, but faces a no-win situation. Ignoring the Houthis subjects international trade to a Houthi veto. But direct attacks on Houthi targets in Yemen represent a dangerous escalation, embarking the United States on a conflict that it cannot win simply through military might. Ultimately, Washington’s best hope may be to seek diplomatic solutions based on Israeli–Palestinian de-escalation, which makes sense on its own terms. But even if U.S. diplomatic efforts succeed, things may never be the same in the Red Sea.

Strangling Red Sea Trade to Save Gaza

For nearly three months, the Houthi movement in Yemen has been attacking merchant vessels near the Bab al-Mandab Strait, a key shipping choke point on the southern end of the Red Sea. The attacks have forced shipping companies to reroute around Africa, causing considerable economic harm. To the Houthis, the attacks are a way of pressuring Israel and its U.S. ally to stop the war in Gaza, which began after Hamas killed some 1,200 Israelis on October 7. Since then, close to 25,000 Palestinians have been killed and violence has sprouted across the Middle East, from Lebanon to Syria and Iraq.

Militant Islamists allied to Iran, the Houthis have ruled Yemen’s capital, Sanaa, and much of the Yemeni Red Sea coast for years. They aren’t internationally recognized as a legitimate government, however, and Yemen remains mired in civil war. Previously, Houthi attacks have focused on their Yemeni rivals and on the states backing them, including Saudi Arabia and the United Arab Emirates, but violence has ebbed since 2022.

When Israel attacked Gaza in October, the Houthis followed the example of other Iran-backed, Hamas-allied groups by joining the fray, first by firing drones and missiles at the Israeli Red Sea port city Eilat. Israel’s October 31 takedown of a Houthi ballistic missile has been billed as the first known instance of warfare in space, but the Houthi attacks’ novelty value wasn’t matched by any meaningful strategic effect. Most drones and missiles were shot down by air defense systems in Israel or on U.S. warships, and the ones that actually hit Israel were barely noticed amid the rocket barrages coming out of Gaza and the surging violence on the Israel–Lebanon border.

On November 19, the Houthis shifted gears through a dramatic, helicopter-borne hijacking of an Israeli-linked car carrier transiting Bab al-Mandab. The group said all Israeli-linked ships would be considered fair game, adding that foreign warships that tried to intervene could also be targeted. It was unclear how careful the Houthis intended to be about ascertaining a ship’s links to Israel, but that ambiguity was probably intentional. Their target was not so much Israel or specific shipping companies as international trade, as such.

In practice, the Houthi strategy seemed to be about goading the United States into a no-win fight in Yemen, which they knew that U.S. leaders didn’t want. That, in turn, was their way of pressuring the White House to rein in its Israeli ally.

One of the world’s most crucial waterways, the Red Sea carries some 15 percent of global shipping and 30 percent of the container trade. It is also a critical corridor for Persian Gulf oil and gas going to Europe. When a container ship got stuck in the Suez Canal in 2021, it wrought billions of dollars in economic damage and rattled global markets.

Although many Houthi strikes missed their target and U.S. destroyers in the area shot down several drones and missiles—putting strain on hard-to-replenish air defense systems—some strikes inevitably slipped through, damaging several commercial vessels in November and early December. The Houthis then escalated further by announcing that they might strike any ship suspected of heading to an Israeli port. It greatly added to the uncertainty about who might be attacked, and most major shipping firms now began to steer clear of the Red Sea.

The Drift to War

On December 18, the United States launched Operation Prosperity Guardian, an ad hoc coalition spun out of an existing U.S.-led maritime security effort based in Bahrain. But although shipping giants like Maersk and CMA-CGM were willing to test U.S. assurances by resuming Red Sea transit in late December, the Houthi attacks did not cease. A growing chorus of experts warned that naval air defenses and escorts could not solve the problem. On January 2, 2024, Maersk again suspended Red Sea passages, after one of its vessels had taken a ballistic missile hit.

From that point on, things moved inexorably toward war. U.S. helicopters had killed ten Houthi sailors trying to hijack a ship on New Year’s Eve, drawing Houthi promises of retaliation. On January 3, the United States and fourteen other nations released a joint statement warning the Houthis of unspecified “consequences” unless the attacks ceased, but on January 10, the Houthis dispatched a drone swarm in what amounted to their first publicly admitted attack on a U.S. warship, citing the killing of their sailors. The UN Security Council then adopted a resolution that condemned the Houthi attacks, but the group shrugged it off, launching yet another ballistic missile—its twenty-seventh attack, by the U.S. military’s count.

The stage thus set, a U.S.-led coalition launched strikes on the night of January 11–12, pummeling Yemeni targets with submarine and ship-fired cruise missiles and F-18 jets flying off of the USS Eisenhower, a Nimitz-class carrier in the nearby Gulf of Aden. The Houthis immediately warned that this American aggression, as they termed it, “would not pass without a response.”

Degrading but Not Deterring

The U.S.-led campaign may succeed in taking out many—perhaps most—Houthi launch sites and radars. If sustained, it could perhaps seriously degrade the group’s ability to harm Red Sea shipping. Iran’s ability to help the Houthis restock could also be hampered by intensified monitoring of known smuggling routes across the Gulf of Oman.

That said, a campaign of aerial bombing and cruise missile strikes seems unlikely to deter the Houthis from continuing to try, with whatever resources they retain, to threaten Red Sea shipping. They have other means at their disposal, as well, including uncrewed explosive boats and naval mines.

Fundamentally, any U.S. attempt to intimidate the Houthis seems to suffer from a mismatch between their respective levels of commitment.

The U.S. government has tried to avoid sideshow escalations at a time when it worries about the Gaza War erupting into regional conflict. The current U.S. administration’s main policy prescription for the Middle East has been to seek stability, and Biden came into office hoping to reduce tensions with Iran and in Syria, Iraq, and Yemen, so that America would be able to turn its attention to international problems of greater consequence for itself—chief among them Russia’s invasion of Ukraine and China’s belligerent attitude in east Asia. Though it would be impossible for the United States to ignore the Red Sea challenge and abandon freedom of navigation, the Biden administration clearly has no appetite for a sustained war in Yemen—especially not in an election year.

The Houthis, by contrast, appear to relish the prospect of a well-timed little war with the United States. Standing up for Palestine boosts their popularity and confronting the United States is totally in line with their political credo, summed up in a somewhat cartoonish but very sincere five-line slogan: “Allahu Akbar, Death to America, Death to Israel, Curse the Jews, Victory to Islam.”

In fact, war with the United States might not seem very risky from a Houthi point of view. They may be a bunch of reactionary fundamentalists, but they read the papers. They are well aware of Washington’s reluctance to sink resources into Yemen, and after two decades of on-and-off insurgency and years of Saudi and Emirati airstrikes, they’re confident in their ability to cope with conflict.

Judging by their actions and rhetoric, the Houthis likely priced in the risk of a U.S. military response long ago. They seem convinced that any intervention will be limited enough in scope for them to endure the material damage and come out on top politically.

And as much as the United States would want it to, this won’t be a one-way war. The Houthis can’t do much to fend off U.S. air and missile strikes, but they have regional allies, including Iran, that may help them escalate in precisely the ways that the United States hopes to avoid. Ships or aircraft could be hit by mines, missiles, or drones farther afield, and America’s allies may start to suffer unclaimed attacks of uncertain origin.

Although some of the Houthis’ regional enemies likely encouraged U.S. action, others seem wary at the prospect of major disturbances in and around Yemen. In 2015, Saudi Arabia led a regional coalition in an ill-fated intervention against the Houthis, but the kingdom now seems more interested in sustaining the intra-Yemeni ceasefire and extricating itself from a war it wasn’t winning. It’s not just that Arab states fear that aligning with the United States could prompt Houthi attacks on their own cities and infrastructure, it’s also that they worry about being blamed for what many Arabs view as a U.S.-led war to defend Israel.

Gaza Is Key

That is what it all comes back to: Gaza. With thousands of Palestinians dead and Gaza in ruins, suffering widespread starvation, the Houthi demands powerfully resonate not just in Yemen but across the Middle East and beyond. The Biden administration has brushed off the global outcry, backing its ally to an extreme degree by defending brutal Israeli tactics and shipping weapons to help Israel keep the war going. Strikingly, the United States is even diverting ammunition from Ukraine’s defense against Russia.

But though they may be out of tune with international opinion, U.S. officials are not insensitive to the damage Israel’s offensive has done to their regional position. Behind the scenes, American diplomats have tried to persuade Israel to shift to less gruesome tactics from January onward. Israeli officials seem willing to scale down their operations, but they vow to continue the war in some form and are also warning that Lebanon may be next in line for invasion.

But until the carnage in Gaza ends, any serious resolution of the Red Sea crisis seems unlikely. The United States and its allies could of course keep the strike campaign going for a long time, picking off radar and launch sites as they’re discovered while having warships on guard in the Red Sea—but policing the Yemeni mountains risks becoming an open-ended undertaking. The Houthis and their allies may also respond asymmetrically, unpredictably, and out-of-area—and if the United States fears regional escalation, that risk now seems to have increased.

Conversely, de-escalation in Gaza—in the form of a sustained truce enabling hostage and prisoner releases and a surge in aid delivery—could ideally create opportunities for a face-saving Houthi climb-down in the Red Sea, too. Given that the United States now seems to want Israel to wind things down anyway, it would make sense to use any progress on that to construct an off-ramp from the Red Sea conflict.

Then again, if it depends on post-October 7 Israel and the Houthis both acting with reason and restraint, then finding a solution may be easier said than done.

The Longer-term Problem

In the longer run, the most troubling fact about the Houthi attacks may be that they’re just a manifestation of the new normal.

Since November 19, the Houthis have demonstrated an ability to seriously threaten Red Sea shipping. It’s possible that the United States and its allies will be able to contain that threat or, at least, bring it down to manageable levels. But a precedent has been set: having done it once, the Houthis could do it again. The ability to disrupt global shipping will remain part of their repertoire, for as long as they can spot targets and have the long-range weapons needed.

The Houthis use Iranian-designed ballistic and cruise missiles that aren’t readily available on the global arms market and are not easily crafted by a non-state actor. Most of their attacks, however, rely on Iranian-designed drones. They are also fairly impressive pieces of machinery, but, depending on your desired payload, range, and level of sophistication, not as difficult to copy as the missiles.

New technology is notoriously difficult to put back in the box. In years ahead, long-range weapons tech seems likely to continue to proliferate among non-state insurgent groups, allowing them to hold state and commercial assets at risk in new ways. Around narrow waterways like the Red Sea, that might mean threatening global shipping. Elsewhere, it could be the ability to target airports, government buildings, power plants, and other critical infrastructure.

In short, the Houthi threat to Red Sea shipping is unlikely to pass even after it has been paused. For most of human history, it just wasn’t physically possible to sink Red Sea ships at scale from the shores of Yemen. But now, thanks to developments in missile and drone technology, it is. And given that such technology has proliferated into Houthi hands and been shown to work efficiently, the problem is now as unlikely to go away as the Houthis themselves.

Handling this long-term change in the Red Sea security environment will require precautions and planning, to create military options and economic and logistical safeguards, but also politics. Whether in Yemen or in the wider region, it means trying to solve—or at a minimum reduce, manage, and contain—the conflicts that would bring these weapons back into play.

Header image: A United Kingdom air force Typhoon aircraft takes off on January 11 from Cyprus to join the U.S.-led coalition to conduct air strikes against Yemen’s Houthi rebels. Source: U.K. ministry of Defense via Getty Images.