Game Changer: U.S. concurs Syria used chemical weapons

White House officials notified Congress today that the U.S. believes Syria used sarin gas on its own people, crossing President Obama's "red line" in a potentially game changing acknowledgement that could draw the U.S. into the Syrian civil war.

"It violates every convention of warfare," Defense Secretary Chuck Hagel said, in making the announcement public on Thursday, while visiting the United Arab Emirates. 

The announcement comes days after an Israeli general during Hagel's visit earlier this week declared that Syria had used chemical weapons, which followed similar declarations from Britain and France. Hagel and U.S. officials, put on the spot, previously said U.S. intelligence was inconclusive.

"As I have said, the intelligence community has been assessing information for some time on this issue, and the decision to reach this conclusion was made in the past 24 hours," Hagel said, "and I have been in contact with senior officials in Washington today and most recently the last couple of hours on this issue."

"We cannot confirm the origin of these weapons, but we do believe that any use of chemical weapons in Syria would very likely have originated with the Assad regime."

Miguel Rodriguez, director of the Office of Legislative Affairs, in a letter to Sen. John McCain, R-Ariz., wrote, "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."

Rodriguez cautioned that President Obama would require further investigation of the evidence before deciding how to react, but said the U.S. remains "prepared for all contingencies" to respond to any "confirmed" use of chemical weapons.

A senior administration official briefing reporters in the afternoon would not say what President Obama would do, if the U.S. confirms Syria's use of chemical weapons to its own higher "standard of evidence."

"I don't want to get into those hypotheticals at this juncture," the official said.

But Rodriguez, in the letter to Congress, wrote, "No option is off the table."

"However, precisely because the president takes this issue so seriously, we have an obligation to fully investigate any and all evidence of chemical weapons use within Syria," he wrote. "Given the stakes involved, and what we have learned form our own recent experience, intelligence assessments alone are not sufficient -- only credible corroborated facts that provide us with some degree of certainty will guide our decision-making, and strengthen our leadership of the international community."

The White House said the assessment was made from "physiological samples," but cautioned "we cannot confirm how the exposure occurred and under what conditons."

On Wednesday, McCain sent a letter to Obama demanding a straight, and public, answer on Syria's chemical weapons use, co-signed by Sens. Carl Levin, D-Mich., Bob Corker, R-Tenn., Bob Menendez, D-N.J., Saxby Chambliss, R-Ga, Bob Casey, D-Penn., Lindsey Graham, R-S.C., and Kelly Ayotte, R-N.H. 

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