ARI SHAPIRO, HOST:
We're going to turn now to Siegfried Hecker. He is a nuclear scientist who has been tracking the nuclear program in North Korea for decades. He's seen the country's nuclear facilities firsthand. He's now an emeritus professor at Stanford University, and he sees some promising signs in relations between the U.S. and North Korea. Welcome.
SIEGFRIED HECKER: It's my pleasure, Ari.
SHAPIRO: You and some of your colleagues at Stanford have made this elaborate chart showing where in the U.S.-North Korea relationship there is red - danger, chance of war - to green, where things look a little more promising. You've been tracking lots of different aspects of this nuclear relationship. Explain, just in the last couple years, what has changed?
HECKER: By the end of the Obama administration in 2016, almost all of our indicators had turned red. And in 2017, the first year of the Trump administration, they turned deep red. And...
SHAPIRO: That was when President Trump was saying little rocket man and things like that.
HECKER: Precisely. Not only was the political situation such that it was red and great tension, but also, North Korea made significant progress in its nuclear and its missile program. And now we just released the 2018 chart. Believe it or not, what happened is quite a few of the indicators turned less red, and some of them turned green.
SHAPIRO: There are about a dozen indicators here, ranging from diplomacy to plutonium enrichment to missiles, sanctions. Tell us where you see things improving.
HECKER: Yeah. So since I'm a nuclear guy, we don't just talk about nuclearizing or denuclearizing. I like to stress the three components of a nuclear arsenal - the bomb fuel, the - what we call weaponization - that's design, build and test - and then the delivery - the missiles. So as we track those - for example, on the bomb fuel, North Korea has continued to make highly enriched uranium and plutonium. So that's still deep red.
However, on the weaponization, it's cranked back one. And the reason is that in 2017, they were making enormous progress, including what was likely a test of a hydrogen bomb. And then they ended testing. And if you end testing, as far as I'm concerned, you don't have a militarily useful hydrogen bomb.
And then in the missiles, likewise, they were making significant progress on ICBMs. Actually, they tested some submarine-launched missiles. They ended missile testing. And therefore, that's also rolled back. In the diplomacy world, there were many things that had turned quite dark green because the Singapore summit, North-South relations.
SHAPIRO: In your opinion, how much of this positive movement has to do with President Trump himself?
HECKER: Well, that's very difficult to tell. The one thing that I would say - the single most important thing to change the whole tenor of the relationship and the threat was the Singapore summit. The Singapore summit was exactly the right thing to do to actually lower the tensions between North Korea and the United States. Then, that led to a lot of moves from North Korea, such as the end of missile testing and of nuclear testing. And so, you know, whether we like it or not, we have to admit that those were steps in the right direction.
The question was, you know, can one actually follow up? That was difficult in 2018. You know, I have reason to believe that we can be more optimistic in 2019.
SHAPIRO: What about the argument that the U.S. is giving North Korea a real public relations win - a prominent meeting with the president of the United States before the entire world - without getting a concrete concession from North Korea in return for that?
HECKER: They already have a concession. That concession is an end of testing. And that is significant. In terms of giving Kim Jong Un, you know, that spotlight in the world, if it makes him a more responsible leader, if it makes North Korea to allow in some sunshine and some cooperation, my view is that's actually a step in the right direction.
SHAPIRO: Siegfried Hecker is a senior fellow emeritus at the Center for International Security and Cooperation at Stanford, speaking with us today on Skype. Thanks so much for your time.
HECKER: You are very much welcome, Ari. Transcript provided by NPR, Copyright NPR.