The United States appears headed for an almost certain military intervention in Syria following allegations that President Bashar al-Assad had used chemical weapons on opposition forces and civilians.
However, while government officials, and President Obama himself, have publicly said it is clear Assad's forces carried out that attack, they have yet to produce hard evidence establishing the link. And privately, multiple U.S. intelligence officials have cautioned that the evidence is "not a slam dunk," according to the Associated Press — a reference to former CIA Director George Tenet's 2002 claim, later disproved, that the evidence tying Iraq to weapons of mass destruction was just that.
On Wednesday, Obama told PBS that the U.S. had "concluded" that the Syrian government was behind the attacks.
"We do not believe that, given the delivery systems, using rockets, that the opposition could have carried out these attacks," he added.
Days prior, Secretary of State John Kerry said the existing evidence and reported deaths "strongly indicate" Syria used chemical weapons. And back in June, the U.S. said it had "high confidence" Assad was behind another reported chemical weapons attack.
Yet the Associated Press' Kimberly Dozier and Matt Apuzzo, citing several anonymous government officials, wrote Thursday that a report from the Office of the Director of National Intelligence on the attacks was "thick with caveats." While it was all but certain chemical weapons had been used, gaps in U.S. intelligence made it hard to directly tie Assad to their use.
More from the Associated Press:
Over the past six months, with shifting front lines in the 2½-year-old civil war and sketchy satellite and human intelligence coming out of Syria, U.S. and allied spies have lost track of who controls some of the country's chemical weapons supplies, according to one senior U.S. intelligence official and three other U.S. officials briefed on the intelligence shared by the White House as reason to strike Syria's military complex. All spoke on condition of anonymity because they were not authorized to discuss the Syrian issue publicly.
U.S. satellites have captured images of Syrian troops moving trucks into weapons storage areas and removing materials, but U.S. analysts have not been able to track what was moved or, in some cases, where it was relocated. They are also not certain that when they saw what looked like Assad's forces moving chemical supplies, those forces were able to remove everything before rebels took over an area where weapons had been stored. [Associated Press]
Israeli intelligence operatives have reportedly intercepted communications between Syrian officials discussing a chemical attack. However, that correspondence was between "low-level staff," according to the AP, leaving open the possibility that rogue elements of the military carried out the attack on their own.
Still, the U.S. has argued that if any element of the Syrian military ordered the attack, the blame would fall on Assad.
"The commander in chief of any military is ultimately responsible for decisions made under their leadership," Marie Harf, a State Department deputy spokeswoman, told the New York Times.
Meanwhile, British Prime Minister David Cameron's push for a swift response was hamstrung by legislators unconvinced he had produced "compelling evidence" to warrant such a strike. And a British intelligence assessment released Thursday said the U.K. had only a "limited but growing body of intelligence" linking Assad to the use of chemical weapons, hardly a convincing affirmation of certitude.
United Nations investigators are investigating the reported sites of the chemical weapons attacks, but have yet to announce their findings.
Obama's national security team will brief key members of Congress on the evidence against Syria later Thursday. The administration is expected to make that evidence public as early as Thursday as well.