A man walks next to a hole made by a Saudi-led airstrike on a funeral hall, in Sanaa, Yemen, on Monday. (Hani Mohammed/Associated Press)

THE HORRIFIC bombing of a funeral ceremony in Yemen on Saturday has forced a long-overdue reexamination by the Obama administration of its support for the air war being waged there by Saudi Arabia. For 18 months, the Saudis and their Persian Gulf allies have tried to bomb Iranian-backed Houthi rebels and their Yemeni allies into submission, with the help of intelligence, refueling and munitions supplied by the United States. The result has been a military stalemate as well as more than 4,000 civilian casualties — including more than 140 killed in the Saturday airstrike.

Like Russia in Syria, Saudi Arabia has repeatedly hit hospitals and other civilian targets. So it is more than plausible that the attack on the funeral, which was attended by numerous Houthi leaders, was deliberate. Under pressure from top U.N. officials, who called for an international investigation, Saudi authorities said they would stage one of their own. That’s unlikely to be satisfactory — and neither will the promised U.S. review of security cooperation with the Saudi coalition in Yemen, unless it leads to the end of such attacks.

Saudi Arabia’s Sunni regime perceives Yemen’s civil war as a proxy conflict with Shiite Iran, even though the Houthis are allied with Yemen’s former Sunni president, a onetime Saudi ally. The United States, too, has interests at stake: The rebels toppled a U.S.-backed government and disrupted operations against the Yemeni branch of al-Qaeda. On Sunday, Houthi forces fired two missiles at a U.S. destroyer in international waters off the Yemeni coast; both missed.

From its inception, however, the Saudi military campaign — directed by the ambitious 31-year-old deputy crown prince, Mohammed bin Salman — has been misconceived. Aimed at driving the Houthis out of the capital, Sanaa, it had no chance of succeeding without a substantial ground force, which the Saudis lack. Peace talks this year appeared to make progress toward a compromise solution, but when they broke down in August, the bombing resumed. According to the United Nations, at least 369 civilians have been killed or injured since the beginning of October — including a number of Houthi leaders who supported the peace talks.

Though ambivalent about the Saudi intervention, the Obama administration has aided it in part because of a perceived need to bolster the U.S. alliance with Riyadh following the Iranian nuclear deal. Pentagon officials have tried to restrain attacks on civilian targets, even supplying lists of facilities that should not be struck — something Russia surely has not done in Syria. Still, the administration did not apply the leverage it has following the previous bombings of hospitals; by withholding intelligence and refueling, Washington could quickly curtail, if not completely halt, the Saudi campaign.

Following the weekend attack, Secretary of State John F. Kerry called Prince Mohammed and the Saudi foreign minister to press for an immediate “cessation of hostilities.” The Saudi response was predictably qualified. Mr. Kerry also called for steps to ensure that “such an incident does not happen again.” If they are not taken, U.S. military support must cease.