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From NPR News, this is ALL THINGS CONSIDERED. I'm Audie Cornish.
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And I'm Melissa Block. The Obama administration has now joined France and Britain in concluding that the Syrian government has used chemical weapons against its own people. That crosses a red line that President Obama has repeatedly warned would change the U.S. calculation in Syria.
Tonight, the administration announced that it will step up its military support for the Syrian rebels. And joining us now to explain what that means is NPR's Scott Horsley, from the White House. Scott, first, there has been suspicion of chemical weapons used by the Syrian regime for months now. What has changed?
SCOTT HORSLEY, BYLINE: That's right, Melissa. The president has long said the U.S. needs more than just a suspicion of chemical weapons use. It needs solid evidence that it can take to the international community. This administration is haunted by the claims that President Bush and his team made about weapons of mass destruction in Iraq, that turned out to be false. So for months now, the intelligence community has been trying to build a rock-solid case.
And the White House now says it has the evidence to say with high confidence, that the Assad regime in Syria has used chemical weapons, including the nerve gas sarin, on multiple occasions during the last year.
The White House has documented between 100 and 150 people who have been killed in Syria, using chemical weapons. That's not the full tally; there are probably more. Now, in any case, that's still a tiny fraction of the 93,000 people who have been killed overall in that conflict. But the use of chemical weapons does violate longstanding, international norms.
BLOCK: And Scott, just to clarify, did the administration explain what the evidence is that they're saying now, they consider to be rock solid?
HORSLEY: Well, they've said it comes from multiple streams of evidence, lots of different kinds of evidence, and one type is forensic evidence.
BLOCK: President Obama has long said that the use of chemical weapons would constitute the red line that we mentioned. And now that he apparently is confident that the Syrian regime has crossed that line - of course, the question is, what does he do in response?
HORSLEY: Right. Well, the White House has said they have already been increasing aid to the opposition in Syria, both the political and the military opposition. But now, with this newfound confidence, White House adviser Ben Rhodes says the president has decided he will provide military aid to the Syrian rebels. The administration is not detailing exactly what that aid will consist of, but they do say it will - that both the nature of the aid, and the scale of the aid, will be different than it has been up until now. And that change was prompted, they say, by the use of chemical weapons.
Now, there could also be additional action from the international community. The U.S. is sharing this information with the United Nations. The president will be talking with his allies next week, when he's at the G-8 summit in Northern Ireland. But on its own, the U.S. has made the decision to begin supplying military aid to the Syrian opposition - which, of course, has been on the losing end of the recent fighting there.
BLOCK: We did hear tonight from Republican Sen. John McCain that in his view, simply arming the rebels will not be enough to change the equation on the battlefield. Is the White House prepared to go further?
HORSLEY: Well, the U.S. will continue to evaluate its options, including military options. But as of now, the president has not made the decision to pursue a U.S. military operation such as a no-fly zone. Ben Rhodes stressed that would be a heavy, open-ended commitment; more complicated, he says, than what was done in Libya. So while the White House is, by no means, ruling out a no-fly zone or other military action in the future, for now the president has not made that decision. The decision he has made is to supply new military support for the opposition. Anything beyond that, we'll have to wait.
BLOCK: OK. NPR's Scott Horsley, at the White House; Scott, thanks very much.
HORSLEY: You're welcome. Transcript provided by NPR, Copyright NPR.