President Trump on Sunday announced that Abu Bakr al-Baghdadi, the elusive Islamic State commander, died during a U.S. military operation in Syria, an important breakthrough more than five years after the militant chief launched a self-proclaimed caliphate that inspired violence worldwide. 

“Last night, the United States brought the world’s number one terrorist leader to justice,” Trump said in a televised announcement from the White House. “He was a sick and depraved man, and now he’s gone.” 

In what the president called a “dangerous and daring” nighttime operation, helicopters inserted a team of American Special Operations troops into a volatile area of northwest Syria, where they began an assault on a militant compound culminating in a retreat by Baghdadi into an underground hideaway. There, in a “dead-end tunnel,” Trump said, the militant leader detonated an explosive vest, killing himself and three of what were believed to be his at least six children. 

The high-risk operation brings a dramatic end to a years-long hunt for the man who spearheaded the Islamic State’s transformation from an underground insurgent band to a powerful quasi-state that straddled two countries and spawned copycat movements across several continents.

At its peak, the Islamic State controlled an area the size of Great Britain, boasting a massive military arsenal and a formidable financial base it used to threaten the West and brutalize those under its control. While the group gradually lost territory to U.S.-backed Syrian and Iraqi fighters, officials cautioned that it remains a potent insurgent force, even after Baghdadi’s death. 

As President Trump announced the death of ISIS leader Al-Baghdadi on Oct. 27, government officials respond to what this means and what comes next. (Mahlia Posey/The Washington Post)

Officials said U.S. intelligence had tracked the militant leader, a onetime academic and veteran jihadist who spent a year in a U.S.-run prison in Iraq, to a redoubt in Syria’s Idlib province, a restive area near the border with Turkey that is home to an array of extremist groups. A critical piece of information on Baghdadi’s whereabouts came from a disaffected Islamic State militant who became an informant for the Kurds working with the Americans, according to a U.S. official who, like others, spoke on the condition of anonymity to discuss a sensitive operation.

The Kurdish-led Syrian Democratic Forces (SDF), whose troops have fought alongside U.S. forces, indicated that they had provided intelligence for the operation.

“For five months there has been joint intel cooperation on the ground and accurate monitoring, until we achieved a joint operation to kill Abu Bakir al-Bagdadi,” its commander, Gen. Mazloum Abdi, said on Twitter, using an alternate spelling of the terrorist leader’s name.

Trump has been accused of abandoning the Kurds following a decision to pull back most U.S. forces in northern Syria, who had provided a deterrent against Turkish forces threatening an attack from across the border. Officials on Sunday suggested that Baghdadi’s death would not affect plans to curtail, or at least alter, the military mission in Syria. 

A senior official from Iraq’s intelligence service, speaking on the condition of anonymity to discuss intelligence, said the arrests and interrogation of people close to Baghdadi also helped yield his location, information that was provided to the Americans.

U.S. intelligence is tracking six Islamic State individuals in the line of succession to Baghdadi, the U.S. official said. It’s as though Baghdadi were the CEO and the six were his “executive VPs,” the official said.

They are dispersed, but U.S. intelligence “generally” knows where they are. The hope is that intelligence gleaned from the material recovered in the raid will help U.S. forces “roll up . . . the leadership cadre” in the coming months.

The ideal time to act is when the leadership ranks are in chaos, as they are now, the official said, and militants’ likely movements or communications provide opportunities to target them.

“We’ll keep picking away,” the official added.

Vice President Pence, speaking to CBS, said he and Trump were first informed on Thursday of the likelihood that Baghdadi would be at the target site, which the United States had been monitoring for some time. The president authorized the mission on Saturday morning.

Officials said that two U.S. service members were lightly wounded in the operation and that additional militants were killed, including two women — identified as Baghdadi’s wives — who were wearing explosive vests. 

The raid comes as the United States scrambles to adjust its posture in Syria in the wake of Trump’s declaration earlier this month that he would pull out nearly all of the approximately 1,000 troops in Syria amid a Turkish offensive against Syrian Kurdish troops who have been the Pentagon’s main battlefield partner there. But evolving plans now call for a larger residual force that could mean a substantial ongoing campaign. 

It also comes as the president faces impeachment proceedings over his role in withholding military aid to Ukraine and as the campaign for the 2020 presidential election intensifies. 

National security adviser Robert O’Brien, speaking to NBC, said it was “a good day for the United States, for our armed forces, and for the president.” 

During his remarks, Trump thanked Syrian Kurdish forces and nations including Russia and Turkey.

Senior officials later sought to minimize the significance of Trump’s mention of Russia, saying the United States had a requirement to consult with Moscow, which is an important backer of Syrian President Bashar al-Assad and operates air defense systems in Syria, to ensure the safety of U.S. troops.

Trump described a harrowing operation that involved firefights before and after U.S. personnel, ferried in under the cover of darkness in eight helicopters, touched down in Idlib province. While the intent of the operation had been to capture Baghdadi, Defense Secretary Mark T. Esper told CNN, he moved underground when U.S. forces called on him to surrender, where he detonated his device. 

Officials said the military had taken DNA samples from Baghdadi’s remains and had quickly conducted visual and DNA tests to determine his identity. Nearly a dozen children were removed from the site, Trump said. It was not clear where they were taken.

“Baghdadi was vicious and violent, and he died in a vicious and violent way, as a coward running and crying,” he said.

Baghdadi’s actions during the operation could not be immediately verified. 

A second official, who spoke on the condition of anonymity to discuss operational details, said that troops from Delta Force, an elite military unit, conducted the operation from a base in Iraq with support from the CIA and Kurdish forces.

The DNA material needed to identify Baghdadi was voluntarily provided by one of his daughters, the official said. 

In his remarks, Trump appeared to relish the opportunity to mark a major foreign policy achievement, reiterating his claims of having single-handedly defeated the Islamic State and making no mention of the Obama administration’s steps to set in motion the campaign that culminated in a series of ground battles that deprived the Islamic State of territory and cash.

Esper, in a separate interview with ABC, praised Trump for making the “bold decision” to authorize the raid and said U.S. forces had rehearsed for several weeks. 

Russia immediately cast doubt on the sense of triumph in Washington.

“An increase in the number of direct participants and countries, which have allegedly joined this ‘operation,’ each of them with totally contradictory details, cause well-grounded questions and doubts that it has really been carried out, and that, what’s more, it has been successful,” said the Defense Ministry spokesman, Maj. Gen. Igor Konashenkov, according to the Interfax news agency.

Trump praised his military and intelligence officials for the operation, which he said he watched from the White House Situation Room on Saturday evening — following a round of golf in the afternoon — with Pence, Esper, Gen. Mark A. Milley, chairman of the Joint Chiefs of Staff, and other senior officials. News that Baghdadi was killed — announced as “jackpot,” from the commander on the ground, according to O’Brien — came around 7:15 p.m. Trump issued a tweet two hours later after U.S. helicopters touched down in Iraq, writing, “Something very big has just happened.” 

In describing the importance of Baghdadi’s death, Trump named American citizens whose executions by the Islamic State first pulled the United States into a military operation against the group, including James FoleySteven Sotloff and Peter Kassig. Pence said the Pentagon leadership had named the operation after Kayla Mueller, an American who died in Islamic State custody and who U.S. officials have said was repeatedly raped by Baghdadi

During the group’s extremist reign, many more Iraqis and Syrians were killed or brutalized. Militants also enslaved women and children from Iraq’s Yazidi minority.

The operation served as a reminder of the grim series of events set off by the rise of the Islamic State and the sophisticated global propaganda and recruitment network that enabled. Among the high-profile acts of global violence the group inspired were the 2015 attacks in Paris and San Bernardino, Calif. The group also used its financial and political power to establish foreign affiliates in places such as Libya. The Pentagon continues attacks against Islamic State fighters in Afghanistan, Yemen and Somalia.

Although Baghdadi, 48, a native of the Iraqi city of Samarra, was not the first leader of the evolving militant organization that eventually became the Islamic State, he oversaw its rise to global prominence in 2014 as it took advantage of instability and weak governance to roll across Iraq and Syria. 

Despite publicly declaring an ambitious extremist vision that same year, Baghdadi remained a distant, reclusive figure even to his supporters. In recent years, he has attempted to usher the organization into a renewed underground phase, urging followers in an audio message last month to attempt to break imprisoned brethren out of jail. 

Sen. Jack Reed (D-R.I.), ranking minority-party member of the Senate Armed Services Committee, was among the Democrats who paired accolades for a successful operation with a warning about the potential impact of Trump’s larger Syria policy. 

“The concern of this hasty withdrawal is that we’re going to lose that connectivity with the Kurds in terms of intelligence gathering,” Reed said in an interview. “I think that’s going to be a very significant loss going forward.” 

Earlier in the day, Sen. Lindsey O. Graham (R-S.C.), who spoke to reporters at the White House, voiced support for Trump’s decision to back away from a full withdrawal from Syria and said the president had told him of his desire to get Baghdadi. 

His death “is a game changer in the war on terror,” Graham said. 

Faysal Itani, a scholar at the Atlantic Council, said the Islamic State’s militant activities had not been enabled by any special powers of Baghdadi but by conditions that remain unchanged in Iraq and Syria, suggesting its potential to rise once more. 

“ISIS’s success is rooted in state failures, sectarian divides, military and intelligence experience drawn from the Baathist security state it emerged from, and an ideology that is coherent and, for some, compelling,” Itani said, referring to the Baath Party of Saddam Hussein, the former leader of Iraq. 

Liz Sly in Los Angeles, Souad Mekhennet in Germany, Sarah Dadouch in Beirut, Kareem Fahim in Istanbul, Mustafa Salim in Baghdad and Shane Harris, Joby Warrick and Ellen Nakashima in Washington contributed to this report.