If I go anywhere near a sensitive site, I probably would be stopped.

Did China conduct secret nuclear tests?

The United States thinks so.

This is sources and methods from NPR.

I'm Mary Louise Kelly every Thursday on this podcast.

We look at some of the week's biggest national security stories with the NPR reporters out there covering them.

This week, I get to welcome back Tom Bowman and Pierre Pentagon correspondent.

How you, Tom?

Good to be here.

And we welcome a new voice to this pod.

And to NPR, Jennifer Pack, our new China correspondent. Welcome.

Hello, hello. Thank you. So let's put a timestamp on this. We're taping. It is a little past 10 a.m.

here on the East Coast, which makes it 11 p.m. where you are in Shanghai. Way past my bedtime.

It's not my bedtime yet. Not yet. All right. Let's get into it. We are talking

today about nukes and about China and the question of whether China conducted a secret nuclear

weapons test back in 2020. The U.S. government shared new intelligence this week on Tuesday,

claiming that that is exactly what China did. Tom, what is the new intelligence this week on Tuesday, claiming that that is exactly what China did.

Tom, what is the new intelligence? What's it say? Well, our colleague, Jeff, Mr. Science,

Brumfield, he was all over this story. So let me take you back to June 2020. And what was thought

to be an earthquake through a detection of a sensor in Kazakhstan was actually, according to the U.S. government, an illicit Chinese nuclear test.

Now, the event originated the U.S. as a China's main nuclear test site, saying there's very little possibility it was anything other than an explosion, a singular explosion, according to this U.S. State Department official

Christopher Young. But, you know, one expert, Jeff spoke with Ben Dando at this Norwegian

...