Saudi Arabia bears the heaviest responsibility for inflaming the conflict. The Saudis began the air war in 2015 with the aim of reinstalling President Abdu Rabbu Mansour Hadi, whom the Houthi rebels had ousted from power. The Saudis consider Iran their main enemy and feared it was gaining too much influence in the region.

An American official told The Times that there was no evidence the coalition had deliberately tried to hit civilians and that poor intelligence and poor targeting were the likely explanation. Even if true, that is no excuse; in fact, such factors are all the more reason to stop the strikes immediately. Before the funeral debacle, coalition strikes had hit a hospital associated with Doctors Without Borders, a school and a potato chip factory. Earlier this year, a United Nations report blamed the coalition for 60 percent of the deaths and injuries to Yemeni children last year.

The Saudis did not inspire confidence by initially denying that their forces were involved in the attack on the funeral and only belatedly announcing an investigation into “reports about the regrettable and painful bombing.”

After the attack, Secretary of State John Kerry asked Saudi officials for an immediate cease-fire and was told Riyadh would do so as soon as possible if the Houthis agreed. The White House announced a review of its support for the coalition, saying it could result in adjustments.

All of this comes at a moment when America’s ties with Saudi Arabia are fraught over Syria and Riyadh’s opposition to the Iran nuclear deal. Mr. Obama has supported the Saudi war effort in Yemen and sold the Saudis a total of $110 billion in arms, including a recent $1.15 billion order for tanks and other weapons, to appease Riyadh’s anger over the Iran deal. The tank sale went forward even though some administration officials have been worried that it could implicate the United States in war crimes. Last month, a Senate effort to block the tank sale failed.