A clearly furious President Obama condemned the Islamic militants who claimed responsibility for beheading an American journalist, vowing Wednesday to beat back "this cancer" and showing no sign of constraining the U.S. military intervention in Iraq.
As 14 new U.S. airstrikes pounded Islamic State positions, the grisly video and photos of a masked militant killing James Foley ricocheted around the Internet and focused global outrage on the Al Qaeda-inspired army that has swept across much of eastern Syria and western Iraq this year.
In the video, the executioner speaks English with a British accent, and U.S. and British authorities scrambled to identify him. British Prime Minister David Cameron told the BBC that it was "extremely likely" the killer was a British citizen.
The tape thus raised fresh fears about the hundreds of recruits with Western passports, including dozens of Americans, who have rallied to the Sunni insurgents' side in Syria and Iraq and may return home to wreak havoc, U.S. and European officials say.
U.S. officials disclosed that the Pentagon had sent a special forces team, with air and ground forces, into Syria this summer in an attempt to rescue Foley and several other American hostages held captive by the militants.
The government had "what we believed was sufficient intelligence, and when the opportunity presented itself, the president authorized the Department of Defense to move aggressively to recover our citizens," Lisa Monaco, the White House counter-terrorism advisor, said in a statement. "Unfortunately, that mission was ultimately not successful because the hostages were not present."
Obama appeared grim when he met with reporters here on Martha's Vineyard, where he is on a family vacation, shortly after U.S. intelligence verified that the video was authentic. He said he had called Foley's parents, Diane and John, and told them that "we are all heartbroken at their loss."
Denouncing "an act of violence that shocks the conscience of the entire world," Obama accused the extremists of also "killing innocent, unarmed civilians in cowardly acts of violence. They abduct women and children and subject them to torture and rape and slavery."
The extremists "speak for no religion," Obama said. "Their victims are overwhelmingly Muslim, and no faith teaches people to massacre innocents. No just God would stand for what they did yesterday, and for what they do every single day."
As Twitter and other social media tried to block the spread of the video, Obama said the United States would "continue to do what we must do to protect our people. We will be vigilant and we will be relentless."
He did not mention the militants' threat to execute Steven Joel Sotloff, another American journalist held captive. Like Foley, Sotloff was shown on the video wearing an orange jumpsuit similar to those worn by detainees at the U.S. prison at Guantanamo Bay, Cuba.
Foley, 40, was working for the website GlobalPost when he was kidnapped in Syria in November 2012. Family members who sought to secure his release believed they were close to winning it when the video appeared Tuesday.
Foley's parents pleaded with their son's executioners to spare other captives.
"We beg compassion and mercy of Jim's captors, for Steven Sotloff and the other captives," John Foley told reporters who gathered outside their home in Rochester, N.H. "They never hurt anybody; they were trying to help and there's no reason for their slaughter."
Secretary of State John F. Kerry, who had met with Foley's parents, said they were "as determined in working towards his release as James had been daring in covering those war zones himself."
"Make no mistake," he added, "we will continue to confront ISIL wherever it tries to spread its despicable hatred." ISIL is one of Islamic State's several acronyms.
The first spilling of American blood since Obama authorized airstrikes on Islamic State positions Aug. 7 comes at a pivotal time for the latest U.S. intervention in Iraq. The White House has steadily deepened its involvement, and has reached out for greater international support. The public outcry over Foley's death may fuel both.
With 84 U.S. airstrikes so far, the Pentagon has greatly expanded its target list in recent days.
After claiming credit for breaking the siege of Mt. Sinjar, where the militants had threatened to kill thousands of refugees, and for protecting hundreds of Americans working in Irbil, the Iraqi Kurdish regional capital, the U.S. escalated attacks, which helped Iraqi and Kurdish forces push the militants back from the country's largest hydroelectric dam.
With the Mosul dam, which is about 300 miles north of Baghdad, now apparently in government control, the latest attacks appeared designed to create a buffer zone around the facility.
The 14 airstrikes near the dam since Tuesday amounted to the second-heaviest bombardment since the U.S. air war began. The Pentagon said warplanes and drones destroyed or damaged six Humvees, three homemade explosive devices, two armed trucks and one mortar tube. All the aircraft returned safely.
With that site secure, Obama may come under pressure to expand the humanitarian mission he initially declared.
Some analysts predicted that U.S. military planners might consider pushing the airstrikes farther west, into the Sunni heartland of Anbar province, where Iraqi tribes once worked with U.S. ground forces against Sunni extremists, turning the course of the American war there.
Islamic State has shown no mercy in its rampage across Syria and Iraq, using beheadings and crucifixions in some areas to terrorize residents. Its brutal tactics against other Muslims it considered heretics were so savage that Al Qaeda's leaders formally disowned the group this year.
The Foley video appeared to bolster international support for joint action against the militants. Germany and Italy announced that they intended to provide arms and ammunition to the Kurdish forces in northern Iraq. France began doing so last week.
U.S. lawmakers expressed sympathy for Foley's family, and some urged Obama to do more before the militants pose a greater threat.
"America and our allies and partners will only be secure when ISIS is defeated," Sen. John McCain (R-Ariz.) and Sen. Lindsey Graham (R-S.C.), two GOP hawks, said in a joint statement. "That means we must get beyond half-measures, tactical responses and defensive actions. We need to develop a comprehensive strategy — political, economic and military — to go on the offensive."
"I do believe that probably more of a robust air campaign is called for," Rep. Paul Ryan (R-Wis.), the GOP vice presidential nominee in 2012, told Bloomberg Television.
House Majority Leader Kevin McCarthy (R-Bakersfield) tweeted that Islamic State "has proven itself to be the purest form of evil and must be confronted head-on."
Sen. Dianne Feinstein (D-Calif.), chairwoman of the Senate Intelligence Committee, also called for a more robust response. "Countering ISIL will demand coordinated and sustained action by Iraq, the United States and the international community," she said in a statement.
British newspapers reported that the masked executioner was believed to be the ringleader of a group of three Britons who were holding foreign captives in the Islamic State stronghold of Raqqa, Syria.
The man, who called himself John, allegedly served as chief negotiator in talks this year to release almost a dozen hostages; they were all released after ransom demands were met. One of the released hostages later said they referred to the three men as "the Beatles" because of their accents.
Cameron, the British prime minister, who was on vacation with his family in Cornwall, returned to London for emergency meetings. "We have not identified the individual responsible … but from what we have seen, it is looking extremely likely that it is a British citizen," he told BBC.
Islamic State has used Westerners in sophisticated recruitment videos. In June, a video showed British and Australian militants urging others to join them in militancy, but none previously showed a beheading.
Foley's parents hesitated when reporters asked if the U.S. government had done enough to bring their son back safely.
Diane Foley said the FBI had been in touch frequently and that U.S. officials listened whenever family members sought to speak to them.
John Foley said he believed Obama was doing the best he could and that the family was satisfied by their phone call with him Wednesday.
"Would I do something differently? Maybe. I don't see the whole picture," he said. "All I'm saying is what we've been doing to date didn't save Jimmy. We don't know if it's going to save Steven or any of the other people" still captive.
"It wasn't enough," Diane Foley said. "So I pray that it will challenge our government to look deeply within and find a way to protect courageous Americans — humanitarians, journalists who do this, who dare to go where they know there's a chance they can be killed or captured."