The Houthis Enter the Iran War and Everything Gets Worse

Predictably, almost inevitably, the Houthis, one of Iran’s most resilient and resourceful proxies, have entered the Iran war. Reports of new Houthi attacks in Yemen and Saudi Arabia are now daily. In attacks the week of August 9, coming after a month of steady escalation, Houthi rebels reportedly killed six people aboard a cargo ship in the Bab al-Mandab on Tuesday, the first fatalities since the Houthis joined the Iran war in earnest. A few days earlier, the Houthis attacked an oil refinery in the Saudi city of Jazan; targeted Saudi-backed forces in the Yemeni port city of al-Mokha, killing as many as seven; and attacked a Tanzanian-flagged ship in the Bab al-Mandab, killing six crew and rescuers. More than the United States or other regional states, the Houthis threaten Saudi Arabia most directly and have now forced the kingdom to respond.

The exact calculus that led the Houthis to wade more fully into this war remains murky. But what we do know is that the Iranian regime—emboldened after withstanding over four months of intensive attacks by the United States and Israel—sent a Mahan Air flight to Sanaa on July 3, the first direct flight between Tehran and Sanaa in a decade. The ostensible reason was to pick up a Houthi delegation and bring it back to Tehran for Supreme Leader Ayatollah Khamenei’s funeral. But according to the Saudi-supported Republic of Yemen Government, the flight also transported Islamic Revolutionary Guard Corps personnel and materiel to Houthi-controlled Yemen, in violation of the UN’s long-standing arms embargo on the Houthis. When regional mediation efforts to prevent another direct flight from Tehran to Sanaa—ostensibly to return the Houthi funeral delegation—failed, Saudi Arabia decided it could not countenance a direct airbridge between Tehran and Sanaa.

On July 13, Saudi Arabia reportedly bombed the runways at Sanaa and Hudaydah airports with another Tehran-Sanaa flight in the air. The Houthis managed to land anyway, and shortly thereafter retaliated by targeting Abha airport in southern Saudi Arabia on July 13. A week later, the Houthis announced a blockade targeting Saudi vessels in the Red Sea, saying the Saudi blockade of Houthi territory had to end. The Houthis followed through on their threats two days later by striking two oil tankers carrying Saudi crude. On July 27, Saudi Arabia claimed that an Iranian-supported militia in Iraq—perhaps in coordination with the Houthis—had targeted energy infrastructure in Saudi Arabia’s Eastern Province, drawing a joint response from Saudi and U.S. fighter aircraft.

This escalation is exactly why Saudi Arabia had always hoped to avoid getting drawn into the Iran war. Saudi leadership knew that Iran and its proxies had the capacity and willingness to strike the most sensitive targets in the kingdom, including energy infrastructure, desalination plants, and even civilian population centers. For a country betting its future on a transformed economy that attracts tourists and investors—and which still depends on oil revenue to fund that transformation—such attacks could be disastrous.

Before the current Iran war, both the Strait of Hormuz and the Bab al-Mandab were wide open to everyone. Even after the war started, and Iran closed the Strait of Hormuz, Saudi Arabia had been able to export about 80 percent of its oil through the Red Sea. This alternate export route, coupled with elevated oil prices, meant the war had limited impact on Saudi Arabia’s energy revenues. That all changed in July when the Houthis turned their belligerent rhetoric into action, targeting Saudi Arabia directly for the first time since 2022, closing the Bab al-Mandab to Saudi ships and vessels carrying Saudi oil, and undermining the advantage of Saudi Arabia’s Red Sea route.

With the Houthis restricting navigation through the Bab al-Mandab, the United States, Saudi Arabia, and the broader global shipping community could face a situation where not one, but two major maritime chokepoints used to export the majority of the Gulf’s petroleum products are subject to manipulation by Iran and its partners.

If the Houthis were simply a proxy of Iran, their behavior could theoretically be subsumed in a ceasefire agreement governing the broader U.S.-Iran war. But the Houthis see themselves as far more than the tool of another country; they regard their movement as an independent Islamic power, no less grounded in religious legitimacy and revolutionary ideology than the Islamic Republic of Iran itself. That makes the Houthis especially dangerous in the current environment because any negotiated agreement to end the Iran war—necessarily imperfect to begin with—will almost certainly not be interpreted by the Houthis as binding on them.

This obliges Saudi Arabia to convince the Houthis—whether through diplomacy or military force—to back down, and in the meantime bolster its own defenses in the south. But with finite military resources, it will need to balance those efforts with protection of its critical infrastructure, particularly in the Eastern Province, where the country’s energy industry is centered, and at the Yanbu port on the Red Sea.

One of Saudi Arabia’s responses has been to expand its array of partnerships beyond its principal alliance with the United States. On July 30, it announced the formation of a maritime coalition to defend freedom of navigation in the Red Sea. A total of 43 countries were initially invited,14 of which, including Saudi Arabia, have joined so far. The United States, notably, has not. Of the 14 countries in the coalition—Bahrain, Bangladesh, the Comoros, Djibouti, Egypt, Jordan, Kuwait, Qatar, Pakistan, Saudi Arabia, Somalia, Sudan, Türkiye, and Yemen—only Egypt, Pakistan, Saudi Arabia, and Türkiye have substantial navies. The others have either small coastal patrol forces or no real navy at all. It is not yet clear which, if any of them, is prepared to bring the naval capacity—or the political will—to respond militarily to Houthi attacks.

If Saudi Arabia feels compelled to respond to repeated Houthi attacks against its ships in the Red Sea and energy infrastructure with a significant military escalation, it could put Saudi and U.S. interests at odds. Thus far, the May 2025 U.S.-Houthi ceasefire has held even amid the Iran war. President Trump almost certainly would not want another front opened in the war—especially one that could cause oil prices to rise even further before the midterms—while the central conflict remains unresolved. And yet, for a Saudi military effort against the Houthis to succeed, U.S. support would be indispensable. This creates a real dilemma for Saudi Arabia, faced with Houthi attacks and provocations on the one hand, and a U.S. administration reticent to broaden the existing conflict on the other.

Whatever happens, Saudi leadership is likely to view Trump’s approach through the lens of previous episodes in which it has felt let down by Washington in its conflict with Iran and its proxies. In 2015 and 2016, the Obama administration pressured Saudi Arabia to back off its air strikes, assessing that it was producing far too many civilian casualties with little impact on the Houthis themselves. In 2019, drone attacks believed to be either from Iran or its proxies in Iraq struck critical Saudi energy infrastructure in Abqaiq and the Khurais oil field; President Trump, after initially saying the United States was “locked and loaded,” chose not to respond militarily. And in 2025, the Trump administration pulled the plug on a U.S. air campaign against the Houthis that had begun during the Biden administration, reportedly without giving advance notice to Saudi Arabia.

Saudi Arabia has been unenthusiastic about the Iran war from the very beginning. The Saudi leadership, happy in principle to see the end of the Iranian regime, nonetheless worried that the war would end not with a new Iran, but with the whole region worse off than before it started. It also knew that the inevitable Iranian reprisals would affect Saudi Arabia and other Gulf states directly, and yet Saudi Arabia had little confidence that the United States would factor the vulnerabilities of the kingdom’s critical infrastructure into U.S. war plans. Those fears turned out to be well founded, and the new Houthi dimension makes everything worse still.

How far Saudi Arabia goes to quell Houthi attacks will depend in part on Houthi escalations and in part on whether it is willing to embark on a renewed anti-Houthi campaign despite a reluctant U.S. administration. But a new entanglement in Yemen is the last thing Saudi Arabia needs and the latest bitter fruit of this ill-conceived war the Saudi people never really wanted.

Michael Ratney is a senior adviser (non-resident) with the Middle East Program at the Center for Strategic and International Studies in Washington, D.C.