WASHINGTON (AP) -- The White House declared Thursday that U.S. intelligence indicates Syrian President Bashar Assad has twice used deadly chemical weapons in his country's fierce civil war, a provocative action that would cross President Barack Obama's "red line" for a significant military response. But the administration said the revelation won't immediately change its stance on intervening.
The information, which has been known to the administration and some members of Congress for weeks, isn't solid enough to warrant quick U.S. involvement in the 2-year-old conflict, the White House said. Officials said the assessments were made with "varying degrees of confidence" given the difficulty of information gathering in Syria, though there appeared to be little question within the intelligence community.
As recently as Tuesday, when an Israeli general added to the growing chorus that Assad had used chemical weapons, White House spokesman Jay Carney said the administration was continuing to monitor and investigate but had "not come to the conclusion that there has been that use."
The Syrian civil war has persisted, with an estimated 70,000 dead. Obama has so far resisted pressure, both from Congress and from within his own administration, to arm the Syrian rebels or get involved militarily. He has, however, declared the use of chemical weapons a "game changer" that would have "enormous consequences."
The White House disclosed the new intelligence Thursday in letters to two senators, but had Defense Secretary Chuck Hagel announce it to reporters traveling with him in the United Arab Emirates. The letters were sent in response to questions from senators of both parties who are pressing for more U.S. involvement, and it marked the first time the administration has publicly disclosed evidence of chemical weapons use.
"Our intelligence community does assess, with varying degrees of confidence, that the Syrian regime has used chemical weapons on a small scale in Syria, specifically, the chemical agent sarin," the White House said in the letters, which were signed by Obama's legislative director, Miguel Rodriguez. He went on to write that "given the stakes involved," the U.S. was still seeking "credible and corroborated facts" before deciding how to proceed.
Two congressional officials said the administration has known for weeks -- and has briefed Congress -- that the CIA and other intelligence agencies have evidence of two incidents of sarin gas use.
A U.S. official said intelligence agencies have had indications of chemical weapons use since March and reached the conclusions made public Thursday about two weeks ago. The two incidents are believed to have occurred around March 19 in the Syrian city of Aleppo and suburbs of Damascus, the official said.
The officials commented only on condition of anonymity because they were not authorized to speak publicly by name.
The White House described the attacks as "small scale," but the full extent of the chemical weapons use and resulting casualties was not immediately known.
Even as Assad has ratcheted up the attacks on his own people, Obama has limited U.S. assistance to non-lethal aid, including military-style equipment such as body armor and night vision goggles. However, he has repeatedly said that the use of chemical weapons, or the transfer of the stockpiles to a terrorist organization, would change things.
"That's a red line for us," he said in August. "There would be enormous consequences if we start seeing movement on the chemical weapons front, or the use of chemical weapons. That would change my calculations significantly."
A senior defense official said the White House letters were not an "automatic trigger" for policy decisions on the use of military force. The official alluded to past instances of policy decisions that were based on what turned out to be flawed intelligence, such as the Bush administration's decision to invade Iraq after concluding that Saddam Hussein had weapons of mass destruction, including nuclear weapons.
Lawmakers from both parties sounded less than patient.
Sen. Dick Durbin of Illinois, a member of the Democratic leadership, was asked what should be done about Assad crossing the "red line." He said, "That's up to the commander in chief, but something has to be done."
And Sen. John McCain, R-Ariz., said, "I think it's pretty obvious that that red line has been crossed. Now I hope the administration will consider what we have been recommending now for over two years of this bloodletting and massacre and that is to provide a safe area for the opposition to operate, to establish a no-fly zone and provide weapons to people in the resistance who we trust."