Of all the collateral damage likely to accrue across the Middle East in the wake of the January 3 U.S. drone attack that killed Iran’s Islamic Revolutionary Guard Corps Quds Force commander Major General Qassim Suleimani, the modest but thus far encouraging efforts to negotiate an end to Yemen’s war are among the most likely.

As Iran contemplates its response, it almost certainly will want to avoid a direct military confrontation with the United States, which would have devastating consequences for the regime in Tehran. Much more likely, then, would be an asymmetric response, one that would provide plausible deniability for the regime by employing resources in the region, such as the Houthi rebels in Yemen.

The Houthis already have demonstrated a disposition to claim responsibility for military action in the region deemed far more likely to be Iranian in origin. They claimed that they launched the sophisticated cruise missile and drone attack against Saudi Aramco oil facilities on September 14, 2019. According to The Wall Street Journal, “Saudi, U.S. and European officials dismissed the claims as an attempt to obscure Iran’s role in the strike. Yemeni fighters, these officials say, have neither the weapons nor the skills to carry out such a sophisticated strike.”

Gulf Arab states were far more circumspect in their responses to the Aramco attack, even as Iranian officials insisted that the Houthis had carried out the strike in response to Saudi Arabia’s continued aggression inside Yemen, where it has been engaged for nearly five years in a military campaign to restore to power the U.N.-recognized government of President Abd Rabbu Mansour Hadi. “If the Yemen war hadn’t existed, Iran wouldn’t have been able to distract away from its responsibilities for the attacks,” a Western diplomat told the Financial Times.

The impact of the attacks on Saudi Arabia’s largest oil-processing facility and a major oil field was significant, producing an almost immediate shift in the kingdom’s approach to Houthi overtures to de-escalate hostilities. In subsequent weeks, Saudi Arabia dramatically reduced the tempo of its airstrikes over Yemen. By November, U.N. Special Envoy to Yemen Martin Griffiths told the U.N. Security Council that “there were almost 80% fewer strikes nationwide than in the two weeks prior,” adding that there had been “entire 48-hour periods without airstrikes” for the first time since the conflict began. Riyadh also acknowledged that it was holding direct talks, and delegations from each side reportedly have been shuttling between the Yemeni and Saudi capitals. In addition, both sides participated in a series of prisoner exchanges.

The killing of Suleimani and a top Iraqi ally, Abu Mahdi al-Muhandis, as they were leaving Baghdad International Airport in the early hours of January 3, threatens to upend this progress. It greatly increases the likelihood that elements within the Houthi movement close to Tehran will be tempted to draw upon the rebels’ substantial arsenal of ballistic missiles and drones to strike deep into Saudi Arabia, a move that would almost certainly scuttle the ongoing peace initiative and ensure the continuation of Yemen’s tragic war.

The Houthis already have conducted multiple attacks on civilian airports in Saudi Arabia. A June 12, 2019 attack on Abha International Airport, about 70 miles from the Saudi-Yemeni border, wounded 26 people. In November 2017, the Houthis fired a long-range ballistic missile that was intercepted by Saudi defense forces near King Khalid International Airport in the capital, Riyadh.

The U.N. Panel of Experts on Yemen, in a letter addressed to the president of the U.N. Security Council on January 25, 2019, stated that beginning in August 2018, it “began noting the deployment of extended-range unmanned aerial vehicles with a range that would allow the Houthi forces to strike targets deep into Saudi Arabia and the United Arab Emirates.”

Thus, the Houthis clearly have the means to cause pain to a close U.S. ally on behalf of Iran, sparing the regime in Tehran the need to engage directly in response to the death of its Quds Force commander and the exposure to U.S. retaliation that such engagement would produce. Whether it has the motivation to do so is a bit less clear, given the steps its leadership has been willing to take in recent months to de-escalate hostilities with Saudi Arabia.

In July 2019, Mehdi al-Mashat, the head of the Houthis’ Supreme Political Council, told officials from the International Crisis Group that “the allegations about the group’s affiliation with Iran are flimsy, and those who make them know they are false.” The steps the Houthis take in coming days and weeks will reveal much about the veracity of Mashat’s comments. In fact, given the sharp uptick in regional tension in the wake of Suleimani’s death, it is incumbent on the leadership of all the parties to Yemen’s conflict to imagine potential scenarios and weigh the pros and cons of actions they might be inclined to take.

At the very least, Saudi Arabia needs to anticipate that the Houthis will conduct some sort of action in support of Iran – perhaps an attack on Saudi civilian infrastructure – and decide what sort of response best serves its long-term security interests. Certainly, in such a case, it will be tempting to retaliate in kind. But absent substantial loss of life, Riyadh may wish to examine carefully the prospect of absorbing the blow and keeping the door open to negotiations with the Houthis, recognizing that ending the war in Yemen is the best way to protect its citizens and national territory.

Similarly, Houthi leaders, who may face considerable pressure from staunchly pro-Iranian elements within the movement’s ranks to deliver a message to the United States by attacking one of its closest regional allies, need to decide what course of action best serves their own interests. Describing the July International Crisis Group conversation with Houthi leaders, April Longley Alley wrote in October that “the Houthis are clear that they would be on Tehran’s side if a regional war erupted and the war in Yemen were still raging. But they also claimed … that they want to de-escalate with Saudi Arabia and that they will remain neutral in a fight if the Yemen war ends.”

The opportunity for tragic miscalculation abounds in the Gulf region. The parties to Yemen’s conflict have an opportunity to avoid such miscalculation, demonstrate restraint, and persist on the path to peace.