U.S. Defense Secretary James Mattis speaks during the second day of the 14th Manama dialogue, Security Summit in Manama, Bahrain October 27, 2018. REUTERS/Hamad l Mohammed. @Adobe Stock Images.

Last week, two top US administration officials, Secretary of State Mike Pompeo and Secretary of Defense Jim Mattis, urged all actors in Yemen’s conflict to adopt a cease-fire within thirty days. This proposal is a welcome starting point for ending Yemen’s four-year conflict. However, in the past week intense fighting has resumed around the contested city of Hodeidah. US pressure on the Saudi-led coalition will be insufficient to end the hostilities. If the proposed cease-fire is to have any chance of leading to peace, the Houthis and their Iranian backers must also commit to a negotiated settlement, a step that they have thus far been unwilling to take. In addition, the United States and the international community must ensure that any settlement includes all local actors entangled in this complex and multilayered conflict.

The US proposal, which calls for an end to coalition air strikes “in all populated areas in Yemen” and the cessation of all “missile and UAV strikes from Houthi-controlled areas into the Kingdom of Saudi Arabia and the United Arab Emirates” was delivered following increased scrutiny of US-Saudi ties in the aftermath of last month’s brutal murder of Washington-based Saudi journalist Jamal Khashoggi. Prior to Khashoggi’s killing, pressure over errant Coalition bombing of civilian targets and Yemen’s rapidly deteriorating humanitarian crisis had been building for months.

Although the United States is not directly involved in Yemen’s conflict, US arms sales, as well as limited targeting and midair refueling support for the Coalition, gives the United States considerable leverage. But that is insufficient. Even if the Coalition were to withdraw tomorrow, Yemen’s local conflicts would likely continue. Prematurely ending Coalition support for Yemen’s internationally recognized government could also create a political vacuum, which would open up the risk of ceding Yemen to Iran. This would be a strategic catastrophe that neither Riyadh nor Washington should permit.

For the proposed cease-fire to work, it should be more than a symbolic announcement; the United Nations should closely monitor the situation and hold violators accountable. Until now, this has not been the favored approach of UN special envoy Martin Griffiths, who has preferred to emphasize both sides’ cooperation as he works toward a comprehensive peace deal. But continuing to seek peace when one party is consistently undermining the prospect of peace is folly.

While Saudi officials have yet to respond publicly to the new initiative, General Mattis said he believes that both the Saudis and Emiratis are ready for peace. “In fact,” he said, “had the Houthis not walked out of the last effort that Martin Griffiths had going, we’d probably be on our way there right now.” And therein lies the problem: Yemen’s government and the Coalition have shown a willingness to negotiate, whereas until now, the Houthis and their Iranian backers have not.

In September, the Houthis imposed last-minute preconditions on unconditional talks with Yemen’s government—a tactic the Houthis have been using since their first war against Yemen’s government in 2004—scuttling the UN-sponsored Geneva conference at the eleventh hour. Despite offering private assurances to Mr. Griffiths that he is committed to peace, Houthi leader Abdul-Malik al-Houthi has publicly and repeatedly discredited the entireUN process as advancing an “American-Israeli” regional agenda—“Death to America” is a slogan the Houthis force their Yemeni subjects to chant—or as serving the interests of “America’s allies,” meaning Saudi Arabia and the United Arab Emirates. At the same time, Iran, which spends comparatively little supplying the Houthis with arms, ballistic missiles, drones, and training, has shown no interest in ending a military quagmire that is costing its archrival Saudi Arabia at least $3 billion per month. The reimposition of the sanctions’ regime on November 4 gives Iran even less incentive to make any compromise in Yemen.

Without leverage over either Iran or the Houthis, there is nothing the United States can do to bring the Houthis to the table and no way to pressure them to accept the outcome of a peace agreement, not even if the Saudis and Emiratis agree to end their disastrous bombing campaign. For the cease-fire to have the slightest chance of success, the United Nations must bring international pressure to bear on the Houthis to negotiate. It can do this by holding them publicly accountable if the Houthis decide to back out of the new talks tentatively scheduled for later this month in Europe. The UN can also pressure Iran by highlighting its ties to the Houthi militias, a relationship which Tehran continues to deny. The US Congress must also recognize that Houthi violations, as much as Coalition air strikes, are to blame for the humanitarian catastrophe in Yemen. Both must be dealt with.

The second pitfall is the international community’s overwhelming focus on regional actors. It is equally difficult to perceive any real peace or cease-fire in Yemen without a broader inclusive process that addresses the local political dynamics. While UN Security Council Resolution 2216 focused on eliminating the Houthi threat to Yemen, there are other risks to peace. The UAE-backed Southern Transitional Council (STC), an informal group seeking independence for South Yemen, could destabilize the entire country and threaten to break it up. All factions, including the Houthis and the STC, must be represented for the UN process to succeed.

It would be a mistake not to welcome the cease-fire proposal as a starting point for new negotiations. The balance of power in Yemen has been shifting against the Houthis for the past year; their horrific abuses and mismanagement of resources have caused many of their fiercest tribal allies to turn on them. This weakness, coupled with concerted UN and international pressure on the Houthis and Iran, could provide an opening for the US proposal to succeed. With Yemen disintegrating, it’s worth a try, even if the chances for success are slim.