美国国家公共电台 NPR VX: The Nerve Agent Used To Kill Kim Jong Nam Is Rare And Deadly（在线收听）

AUDIE CORNISH, HOST:

There are fresh twists today in the apparent assassination of the half-brother of North Korea's leader, Kim Jong Un. The brother, Kim Jong Nam, died last week at an airport in Malaysia. Security footage showed that two women poisoned him. Now today, Malaysian authorities revealed it wasn't just any poison but a chemical weapon known as VX.

Joining me to discuss what to make of this is NPR science editor Geoff Brumfiel. Hey there, Geoff.

GEOFF BRUMFIEL, BYLINE: Hi, there.

CORNISH: So start just by telling me, what is VX?

BRUMFIEL: Well, VX is a colorless, odorless liquid. It's about the consistency of motor oil, and it is extremely deadly. Less than a drop of this stuff on your skin - it'll absorb straight through, and within minutes, you'll start to feel headaches, nausea, tightness in the chest. What it actually does is it disrupts signals between nerves and muscles. That ultimately leads to the paralysis in the muscles you use to breathe and you suffocate. It's a nasty way to go.

CORNISH: How could you use something like that in an airport and have no one else be harmed?

BRUMFIEL: Well, this is the interesting thing about VX. It's a chemical weapon, and when you disperse it, you can hurt a lot of people. But in its liquid form, it's actually kind of safe, I guess you could say. That's because it's very stable. It doesn't sort of off-gas, so no one nearby can be exposed to it. And you can seal it in a bottle and transport it around, take it through airport security. It's very unlikely to go detected. So in a way, it's sort of the perfect weapon for assassinating a single person when it's used in a particular way.

CORNISH: Now, does the use of VX tell us anything about whether North Korea specifically was involved?

BRUMFIEL: Yeah because this is not just any poison. This is a chemical weapon that has been banned under the Chemical Weapons Convention. And most countries, you know, have vowed never to use it. North Korea is one of the few countries that hasn't signed up to the Chemical Weapons Convention. It's believed to have lots of chemical weapons, including VX. So if this use of VX is verified, that would kind of point the finger at the North Korean state in particular as a suspect in this crime.

CORNISH: In the meantime, what more have we learned about why North Korea would want Kim Jong Nam dead?

BRUMFIEL: This is a real mystery. There's not much evidence that this Kim brother was a particular threat. He lived most of his life outside of North Korea. He was a bit of a playboy. Now, there is a theory that China wanting Kim Jong Nam around in case something happened to Kim Jong Un, the current leader of North Korea, the idea being that Kim Jong Nam is part of the dynasty that has ruled North Korea and could be brought in if something happened or to prevent the collapse of the regime.

Kim Jong Un may not have liked that idea and may have wanted to try and head it off by getting rid of his half-brother. Certainly Kim Jong Un has assassinated political rivals within North Korea. We know he's capable of it.

CORNISH: You know, we hear so much about North Korea whenever it tests a missile obviously or a nuclear weapon. Is there any connection between those stories and what happened in Malaysia?

BRUMFIEL: I think there is a way to think about these things all together. I think it's important not to take one's eye off the ball here. I mean the real threat here is North Korea's missile and nuclear program. They have been developing very rapidly. You know, North Korea now has ballistic missiles that pose a significant threat to some of the U.S.'s allies in the region. It's thought that soon they'll have an intercontinental ballistic missile that could reach anywhere inside the continental United States.

And so I think it's important to understand that what we're looking at here is a regime that is increasingly isolated, that is, you know, doing all sorts of things that are on the fringe of what the global community considers acceptable. And it's a dangerous situation.

CORNISH: That's NPR's science editor Geoff Brumfiel. Geoff, thanks so much.

BRUMFIEL: Thank you.