BEIRUT, Lebanon — It didn’t happen in 2016, after a Saudi jet had dropped American-made bombs on a funeral in the Yemeni capital, Sana, killing more than 140 people.
It didn’t happen in 2018, after a Saudi jet hit a Yemeni school bus with an American-made bomb, killing 44 boys on a field trip.
But on Thursday, nearly six years after Saudi Arabia and its Arab allies launched a punishing military intervention in the Arab world’s poorest country, President Biden announced that he was ending U.S. support for the Saudi-led war in Yemen, including some arms sales.
“This war has to end,” Mr. Biden said, calling it a “humanitarian and strategic catastrophe.”
While Yemenis and many others welcomed the decision, many shared a sense that it had come years too late and was unlikely to exert a swift effect.
“It is not like the operations are going to be suspended tomorrow because of this,” said Farea Al-Muslimi, an associate fellow at Chatham House, a London-based research group, who focuses on Yemen and the Persian Gulf. “The Gulf countries already have a lot of weapons, so the decision is symbolic in a lot of ways.”
For a range of other reasons, Mr. Biden’s decision is unlikely to portend a screeching halt to the war, which the United Nations has called the world’s worst humanitarian crisis.
The United States had already reduced much of the military aid it was giving to the Saudi-led coalition. Years of Saudi bombings failed to shake the rebels, known as the Houthis, from their grip on the capital city and Yemen’s largest port. And years of conflict have shattered Yemen, creating a number of smaller conflicts inside the larger one.
“Even if the weapons are put down, there are deeply rooted disputes, grievances, tensions and divisions in Yemen today and more than 30 fronts of armed fighting between different factions,” said Afrah Nasser, a Yemen researcher with Human Rights Watch. “It was the responsibility of the U.S. to have a strong stance on its role, but we need a comprehensive approach to ending the conflict.”
Yemen’s war began in 2014 when the Houthis stormed out of their homeland in the country’s rugged north to take over the capital city and much of Yemen’s northwest. In March 2015, Saudi Arabia, the United Arab Emirates and other Arab states launched a bombing campaign aimed at dislodging the Houthis and restoring the internationally recognized government. Saudi officials confidently predicted back then that the campaign would be short.
Nearly six years later, the goal appears as elusive as ever, after tens of thousands of deaths, the destruction of much of Yemen’s infrastructure and horrifying outbreaks of cholera and hunger bordering on famine.
Throughout the war, U.S. support to Saudi Arabia and its allies angered even many Yemenis who opposed the Houthis. After deadly airstrikes on weddings, funerals and other civilian gatherings, Yemenis often found and circulated photos of fins and other munition scraps showing their American origins.
But the arms sales continued, regardless of who was in the White House. After the 2016 funeral attack, under President Barack Obama, a spokesman for the National Security Council promised “an immediate review” of support for the Saudi-led coalition, saying security cooperation was not “a blank check.”
President Donald J. Trump entered the White House a few months later and built close ties with the leaders of Saudi Arabia and the Emirates, often speaking of the importance of Saudi arms purchases to the American economy, even after the 2018 strike that killed the 44 schoolboys.
Much remained unclear about the Biden administration’s decision to stop military aid. It did not provide specifics on which munitions and services would be halted, and Mr. Biden said the United States would continue to help Saudi Arabia defend itself, without defining which weapons the United States considered vital to the kingdom’s defense.
Still, some experts saw signs in Mr. Biden’s approach to the war that they view as encouraging, including his appointment of Timothy A. Lenderking, a veteran diplomat with extensive experience in the region, as special envoy charged with pushing for a peace settlement.
The emphasis on diplomacy, largely lacking among the senior leaders of the Trump administration, is welcome, said Peter Salisbury, a Yemen analyst with the International Crisis Group. And reducing arms support to one side could make the United States more able to push for a settlement.
“By removing itself from the conflict, the U.S. is better able to position itself as a diplomatic force that is credibly seeking to end the conflict,” he said. “But the difficulty will be in finding a compromise that the majority of the armed and political factions in Yemen believe is acceptable.”
The protracted war has left Yemen deeply divided in a way that could thwart the most concerted peacemaking efforts.
The internationally backed government that the Saudis have sought to restore is basically a government-in-exile, split between the Saudi capital, Riyadh, and southern Yemen and full of officials with little popular base inside the country.
The forces supporting them are a messy coalition of remnants of the national army, tribal fighters, Islamists and separatists who have sometimes fought each other and seem to share little more than a hatred of the Houthis.
And overlaying the conflict are networks of war profiteers with their own armed factions who could serve as spoilers if they felt that peace would be bad for business.
The war’s wounds run deep.
“If the war does really come to an end, that’s a good move,” said Murshid Abu Zaina, 47, who lost 10 relatives in a coalition attack on his uncle’s home in 2016. But he wanted to see Saudi Arabia, the Emirates and “all participants in the aggression on Yemen” held accountable.
“We appeal to God to grant us victory over the enemies of mankind, and over those who collaborated and conspired against Yemen,” he said.
Crafting a peace deal that not only stops the violence but allows Yemen to move forward could prove to be a major challenge.
“It might be possible to end the big war, but it is much, much harder to end the small wars that actually make up the conflict,” said Mr. Salisbury.
A particularly vexing issue is how to end the Houthis’ control of Sana, where it has established its own administration and runs a virtual police state, detaining critics and levying taxes on aid and other goods to fund itself. The group receives military and political support from Iran and has used its control of the north to fire indiscriminate missiles across the border at Saudi Arabia, sometimes killing civilians.
Muhammad Albukhaiti, a political officer in Ansar Allah, as the Houthis are officially known, said in an interview that if Mr. Biden’s declaration was not followed by an end to the war and the free movement of goods to Houthi areas, “it would simply come out as propaganda aimed at shrinking from the moral responsibility for the aggression and the blockade on Yemen.”
The Biden administration notified members of Congress late Friday that it would reverse the action and lift the terrorist designation from the Houthis, according to officials familiar with the decision.
Some experts had thought the designation could be used as leverage to get the group to negotiate.
“In the past, there was no leverage over them, but if you can find the right diplomatic framework, you just might be able to use that,” Mr. Al-Muslimi of Chatham House said before the reversal was disclosed. “They can’t be bombed out of Yemen.”
Ben Hubbard reported from Beirut, and Shuaib Almosawa from Sana, Yemen.