U.N. Special Envoy for Yemen Martin Griffiths sounded relieved in a briefing to the Security Council this week, noting that even after the American airstrike that killed Iran’s Islamic Revolutionary Guard Corps-Quds Force commander Qassem Soleimani, “the immediate crisis seems to be over… Yemen has been kept safe.”

Griffiths may have spoken too soon.

Yemen has been an increasingly important and tragic theater in the confrontation between Iran, the United States, and their respective clients in the Middle East, with Saudi Arabia and the United Arab Emirates at the head of an intervening coalition on one side and the Houthis backed by Iran on the other. What will happen in Yemen following the killing of Soleimani and the escalation in tensions between the United States and Iran? And how can Yemen’s civil war be insulated from the regional fallout?

News emerged late last week that the United States also targeted Abdul Reza Shahlai, a senior Quds commander, in Yemen. Had the strike succeeded, the Houthis or other Iranian-aligned forces in Yemen would almost certainly have had to respond, threatening an unruly escalation spiral. Instead, the operation was unsuccessful, and Iran’s measured reaction was limited to Iraq. Nevertheless, the airstrike is unlikely to have put Houthi leadership in a conciliatory mood.

Ismaeil Ghaani, who served as Soleimani’s deputy for decades, was quickly named Soleimani’s replacement as head of the Quds Force. Following decades of leadership of the Quds Force, Ghaani is unlikely to deviate from Iran’s approach of using proxies to push against opponents in the retaliation for Soleimani’s killing.

At the same time, there is reason to hope that Yemen can avoid Iranian-backed escalation. But avoiding another round of escalation in Yemen’s civil war will require the active participation of the United States and regional actors.

Yemen’s Fragile Status Quo

One year after representatives of the Houthis and of Yemen’s internationally-recognized government agreed to a limited ceasefire as part of the Stockholm Agreement, little concrete progress to implement the agreement has been made: Hodeidah, the port area at the center of the agreement, is still the most dangerous place in the country for civilians. Likewise, the Riyadh Agreement, which sought to patch a split between the official government and southern separatists supported by the United Arab Emirates, is faltering and in danger of total collapse.

Nevertheless, just a few weeks ago there were reasons to be cautiously optimistic that, after years of failed negotiations, the Saudi-led coalition’s intervention in Yemen may have been winding down. Soleimani’s assassination threatens to undo this fragile and halting progress. While Iraq remains the most likely arena for Iranian retaliation against the United States and its partners, Iranian officials also see their relationship with the Houthis as a mechanism for dialing pressure on its opponents up or down while maintaining plausible deniability for any particular attack. Yemen may therefore be a site of Iranian escalation in the coming weeks and months. Indeed, the Houthis expressed support for Iran and promised to respond “promptly and swiftly” to the airstrike. Whatever its form, public retaliation risks upsetting the nascent negotiations over Yemen’s forgotten war.

What Will Happen Now in Yemen?

Iran is well aware that it would be badly overmatched in a conventional conflict, and is therefore likely to avoid all-out war with the United States. Rather, Iran’s leadership is likely to retaliate via the asymmetric resources that Tehran — in an effort led by Soleimani and the Quds Force — has successfully cultivated in the region.

The Houthis have assumed greater importance in Tehran’s regional strategy in recent years. Their geographic proximity to Saudi Arabia (and decades-long history of antagonistic relations) provides Iran with a convenient way to antagonize a long-time rival on its southern border and to retaliate horizontally for attacks on its partners in Syria. The relationship confers what Austin Carson calls escalation control: By maintaining plausible deniability, Tehran can signal its displeasure at American policies while giving opponents a face-saving way to avoid further reprisals, thereby dampening the risk of further escalation. Indeed, the recent strike on Saudi Aramco facilities claimed by the Houthis (but likely perpetrated by Iran) is indicative of this dynamic. The attack allowed Tehran to push back against the Trump administration’s “maximum pressure” campaign while affording both sides an off-ramp.

There are a few reasons to expect that Tehran could turn to Yemen as it formulates its response to Soleimani’s assassination. While Iran’s leadership signaled that its retaliation would end after the missile strikes on bases in Iraq, analysts note that Iran is likely to return to its “forward defense” strategy of working through proxies to push back against what its leadership sees as American aggression in the region.

Ramping up Houthi attacks on Saudi Arabia and the United Arab Emirates would allow Iran to signal its displeasure with Washington while attempting to avoid escalation that could lead to a conventional war. This would be consistent with the forward defense strategy and Tehran’s past behavior in the region. Additionally, by coalescing domestic support, the American strike may empower hardliners in the Iranian regime who favor regional escalation.

And although the Houthis certainly receive significant support from Iran in the form of material support, as well as advice and training from Hizballah operatives on the ground, they are not as strategically close to Iran as other proxies like Hizballah are thought to be. As a recent New America report notes, “there is little evidence of firm Iranian command and control. Iran’s reported provision of missiles and drones shapes the conflict, but its roots are local and would not disappear were Iran to fully abandon the Houthis.” Even U.S. officials have sought to draw a distinction between Iranian and Houthi leadership in recent months.

Yet there are cautious signs that Houthi leadership could be willing to play along by following Iran’s lead in this instance: Just a few days before the assassination of Soleimani, Houthi officials cautioned that targets within Saudi and Emirati territory remain on their list of potential military targets, suggesting a willingness to escalate. And, after the strike, Houthi leadership called for reprisals against the United States.

But the region’s reaction to the Aramco attack — which saw the Emiratis pursuing quiet talks with Iran and Saudi Arabia negotiating with the Houthis — also provides reason to hope that regional actors may work together to head off Iranian escalation in Yemen.

First, the Houthis’ relative autonomy from Iranian command-and-control gives them some leeway to resist pressure to escalate, although the failed U.S. strike in Yemen may affect this calculus. Confronted with the choice of either retaliating on Tehran’s behalf, at the risk of inciting Saudi re-entry into the war, or resisting the external pressure, thereby preserving the odds of a favorable settlement, the Houthi leadership may decide to bet on the latter.

Second, while Saudi commentators delighted in the blow to their regional opponent, the Kingdom has publicly cautioned against escalation and reportedly urged the Trump administration to exercise restraint. This signals that the Arab Gulf states may continue in the more cautiously de-escalatory approach that they have taken on Yemen over the past several months, as the United Arab Emirates and Sudan began to withdraw troops from Yemen, Saudi Arabia negotiated with the Houthis, and the tempo of Saudi airstrikes declined precipitously.

As much as they vehemently oppose Iranian influence in the region, both Saudi and Emirati leadership want to avoid a direct confrontation with Iran, especially after the Trump administration’s erratic policies have made it clear that they may not get American backing in such a confrontation. In other words, the factors that contributed to the intervening coalition’s de-escalatory tendencies a few months ago are still relevant, even after the escalation in tensions between the United States and Iran.

The United States is well-positioned to reinforce de-escalatory dynamics in Yemen and support the nascent peace process there. The recent de-escalation in Yemen has shown that pressure works: Although both the Obama and Trump administrations initially supported the Saudi-led intervention, Congressional threats to leverage arms sales and invoke the War Powers Act to end American material support for the intervention in 2019 subdued Abu Dhabi and Riyadh and opened a new juncture in the conflict. The U.S. military ended its provision of aerial refueling to the Saudi-led coalition following the murder of journalist Jamal Khashoggi in late 2018, and Secretary of Defense James Mattis reportedly pressured Saudi Arabia and the United Arab Emirates to negotiate a political settlement to the war in the lead-up to the Stockholm Agreement. While some of this de-escalatory behavior is attributable to a gradual acknowledgement that this war cannot be won, much can be attributed to U.S. pressure as well. Washington therefore can — and should — continue to pressure its regional partners to reach a negotiated agreement. The recent House vote invoking the War Powers Act with regards to Iran — and supportive statements from a cross-party range of senators — indicates that Congress is willing to maintain pressure on the administration to avoid escalation in the region, even in the midst of ongoing presidential impeachment proceedings.

Players in the region will also continue to play a critical role in Yemen in the weeks and months ahead. Saudi and Emirati leaders are tired of the resource and reputational drain of a war that appears increasingly unwinnable, leading to their willingness to draw down the coalition’s intervention. With international support, regional actors like Oman and even the Gulf Cooperation Council can act as mediators and guarantors to deter potential spoilers and help implement any agreement.

Omani Sultan Qaboos bin Said’s untimely death this past weekend is another potentially complicating factor here. Under Qaboos, Oman has played an important behind-the-scenes role in the negotiations that led to the nuclear agreement, and brokered negotiations between the Saudi Arabia and the Houthis beginning this past fall. Qaboos cut a unique figure in the region, acting as a mediator who had both the stature and credibility to broker agreements between warring parties in the region. His death and the drama around succession created some doubt about whether anyone would be able to take his place. Yet the new sultan Haitham bin Tariq, who was quickly sworn in, has pledged to continue Qaboos’ diplomatic path. Leaders from across the region traveled to Muscat to pay their condolences to the new sultan, cementing the peaceful transition. This continuity is a hopeful sign that Oman can continue to play a productive role as regional mediator.

Finally, policymakers shouldn’t forget about Yemeni actors themselves. While most western analysis of the conflict in Yemen focuses on the third-party intervention, this perspective neglects the indigenous dynamics that led to the outbreak of the civil war in the first place. The focus on external intervention is not without good reason, since regional actors dramatically exacerbated the conflict and prevented an earlier resolution. Yet the civil war in Yemen began over local issues around governance and resource-sharing, and it will not end without solving these underlying issues, thus undercutting potential spoilers.

Additionally, years of fighting has created a patchwork of splintered militia groups and local governance institutions that will prove very difficult to knit back together into a coherent, functioning polity. A resumption of local fighting could act as an invitation for external actors to intervene again, leading to a resumption of conflict. It is therefore essential for mediation efforts to take these local issues into account.

Over the past century, Yemen has often been a site for actors in the region to play out their own conflicts. A relapse in fighting in Yemen could provide future grounds for intervention and will act as a driver of regional instability. By contrast, ending the war in Yemen will eliminate a critical source of Iranian leverage in the Gulf.

Dr. Alexandra Stark is a senior researcher at New America. She was previously a research fellow at the Middle East Initiative, Belfer Center for Science and International Affairs at Harvard University and a USIP-Minerva Peace and Security Scholar.

Image: Wikicommons (Photo by Fahd Sadi)