AUDIE CORNISH, HOST:
The other big story we're following today is what the U.S. might do in Syria. This is after a suspected chemical weapons attack last weekend on a rebel stronghold near Damascus. This is happening just over a year after President Trump ordered a Tomahawk missile strike against a Syrian airfield. American officials said it had been used in a sarin gas attack. This time the initial response is different because there are calls not just from the U.S. but also from Syria as well as its ally Russia for verification of whether chemicals were indeed used.
And joining me to talk about this complicated scenario is NPR national security correspondent David Welna. Hey there, David.
DAVID WELNA, BYLINE: Hey, Audie.
CORNISH: David, the U.S. has been talking with certainty that it was the Syrian president who used these chemical weapons against Syrian civilians. Is that warranted?
WELNA: It is. During the seven years that this terrible civil war has been going on in Syria there have been scores of chemical weapons attacks, and almost all of them have been attributed to Syria's regime. And perhaps most memorable one was one carried out nearly five years ago in which about 1,400 Syrians died in a sarin gas attack in the same area where the attack occurred last weekend. And that was a year after President Obama had warned Syria that carrying out chemical attacks would be crossing what he called a red line.
CORNISH: We hear a lot now about that so-called red line. Can you remind us what actually happened afterwards, though?
WELNA: There was a lot of pressure for a military response to that action. And Russia intervened at the time and urged Syria to join the Chemical Weapons Convention, which bans not just the use of chemical weapons but their production and their storage as well. And Syria did so. But it's been hard for international inspectors to verify whether Syria really destroyed its chemical weapons stockpiles. Human Rights Watch says that Syria's carried out at least 85 chemical weapons attacks since it agreed to do away with them.
CORNISH: And that brings us to last weekend just outside Damascus. What's known about that suspected chemical attack?
WELNA: Well, so far we've only had reports from activists on the ground there and from the Syrian American Medical Society, which operates more than a hundred medical facilities in Syria, about what happened there. Initially the reports were that chlorine gas had been used. It's an agent that wasn't prescribed in the deal five years ago because chlorine can be used for good things such as cleaning and purifying water. It kills its victims by asphyxiation, as if they're having an asthma attack, but only if the gas is in an enclosed space such as a bunker. And it's not clear whether that was the case in this attack. There are also suspicions that sarin gas was used. But Amjad Rass, who's a doctor with the Syrian American Medical Society, says all of that has yet to be determined.
AMJAD RASS: What happened last weekend, we don't know if it was only chlorine or chlorine plus sarin. With sarin we need the testing. We cannot say it's sarin without testing because it does not have a smell, does not have a color, which is different from chlorine. Chlorine smells like chlorine.
WELNA: Dr. Rass says it may be possible to detect the presence of sarin in soil where victims are buried by examining their corpses and even by testing survivors since sarin would show up in their blood for two to three weeks after the attack.
CORNISH: How might we know who carried out the attack?
WELNA: Well, you know, Russia's ambassador to the U.N. claimed yesterday that this attack may have been staged by the rebels themselves knowing that it could lead to U.S. airstrikes against the Assad regime. But this is an area that's been under siege by Syrian government forces for many weeks. And hundreds of people have been killed in conventional attacks, although five other chlorine gas attacks have also been reported there since January. Dr. Rass says the Syrian American Medical Society can only report what it sees on the ground.
RASS: We cannot verify the user of these chemical attacks. We cannot say they're Russians or they're militant. But our activists reported that it came from a helicopter, was dropped by a helicopter.
WELNA: And because only the Syrian government forces and their Russian allies have helicopters, it would appear they were the ones who dropped the bombs that activists say killed more than 40 people in that attack.
CORNISH: Will we be able to really know for sure what happened in that attack then?
WELNA: Well, efforts are being made as we speak to get international inspectors into that area where the attack occurred to see if chemical agents were used. This is different from a year ago when the U.S. attack on the airfield with Tomahawk missiles happened before the inspectors had gone in and verified anything. And the question now, I guess, is whether any punishment would be held off until there's been some verification about exactly what happened there. But in the meantime, it appears that Syrian President Bashar al-Assad got what he wanted. The rebels have capitulated in that area and they've moved out, and the Syrian government is now in control.
CORNISH: That's NPR's David Welna. David, thank you.
WELNA: You're welcome, Audie.
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