ISIS“High degree of certainty” Jihadi John was killed by U.S. airstrike Thursday

The Pentagon confirmed earlier today (Friday) that a U.S. airstrike in Syria targeted Mohammed Emwazi, the ISIS terrorist known as “Jihadi John,” who appeared in several grisly ISIS propaganda videos showing the beheadings of eight hostages.

David Cameron, in a statement from 10 Downing Street on Friday morning, also confirmed the attack.

U.S. military sources said there was a “99 percent certainty” that Emwazi had been killed in the drone strike.

Cameron it had not yet been confirmed that Emwazi was dead, but described the strike as “an act of self-defense” that struck at the heart of Islamic State. Cameron added that Britain had been working “hand in glove, round the clock” with the United States to track down and target Emwazi.

“This was a combined effort, and the contribution of both our countries was essential. Emwazi is a barbaric murderer.”

He said Emwazi had remained a threat to innocent people around the world, adding: “This was an act of self-defense. It was the right thing to do. He was ISIL’s lead executioner, and let us never forget that he killed many, many Muslims, too.””

Emwazi was an “ongoing and serious threat to innocent civilians not only in Syria, but around the world and in the United Kingdom, too,” Cameron said.

Cameron made clear the U.K. government had taken part in the U.S. decision to target Emwazi. “The United Kingdom has no better friend or ally,” he said.

He added, “If this strike was successful — and we still await confirmation of that — it will be a strike at the heart of ISIL, and it will demonstrate to those who would do Britain, our people and our allies harm [that] we have a long reach, we have unwavering determination and we never forget about our citizens.”

The Telegraph reports that Downing Street and the Ministry of Defense sources used a slightly different wording than their American counterparts – either as a result of caution, or the British tendency for understatement — saying that here was a “high degree of certainty that he has been killed.”

Secretary of State John Kerry, in a press conference in Tunis, said that “We are still assessing the results of this strike, but the terrorists associated with Daesh [ISIS] need to know this: Your days are numbered, and you will be defeated,” Kerry said, using an Arabic acronym for the Islamic State. “There is no future, no path forward for Daesh, which does not lead ultimately to its elimination, to its destruction.”

Peter Cook, the Pentagon’s press secretary, announced details of the strike late on Thursday night, saying: “U.S. forces conducted an airstrike in Raqqa, Syria, on 12 November 2015 targeting Mohamed Emwazi, also known as Jihadi John.”

“Emwazi, a British citizen, participated in the videos showing the murders of U.S. journalists Steven Sotloff and James Foley, American aid worker Abdul-Rahman [Peter] Kassig, British aid workers David Haines and Alan Henning, Japanese journalist Kenji Goto, and a number of other hostages.

“We are assessing the results of tonight’s operation and will provide additional information as and where appropriate.”

An AP report quoted an unnamed U.S. official who said that a drone had hit a vehicle believed to be carrying Emwazi in Raqqa in northern Syria. Fox News quoted a senior U.S. military source who said it was “99 percent sure we got him.”

Diane Foley, the mother of James Foley, told ABC News that if Emwazi had been killed in the strike, it would be “really a small solace to us.”

“This huge effort to go after this deranged man filled with hate when they can’t make half that effort to save the hostages while these young Americans were still alive,” she said.

Emwazi was born in Kuwait in 1988, coming to the United Kingdom with his family in 1994, when he was six years old. His parents reported him missing in August 2013. In December 2013 the family was told by the police that he was in Syria, fighting for ISIS.

Experts say Emwazi had no meaningful role in Islamic State’s leadership structure, adding that the impact of his death, if confirmed, could therefore be limited.

“Implications? None beyond the symbolism,” Shiraz Maher, an expert on extremism at King’s College London, said in a Twitter message.

Peter Neumann, director of King’s College’s International Center for the Study of Radicalization, told the Washington Post that Emwazi is a “low-ranking officer” in charge of the facility where the Islamic State holds hostages. But symbolically, Neumann said, his death would show that Islamic State is an organization that is suffering and that it would undercut recruitment.

“It feeds into the narrative of ISIS, in its core territory, losing,” he said.