KELLY: It's CONSIDER THIS FROM NPR. The most heavily bombed country in the history of the world - more than Japan, more than Germany, more than Britain - it's Laos. Between 1964 and 1973, the U.S. dropped more than 270 million cluster bombs on Laos. Here's another way to think about that number. It works out to a planeload of bombs every eight minutes, 24 hours a day for nine years. We brought Lewis Simons into the studio to talk about the legacy of cluster bombs in Laos and what we might learn from it as we eye their use in the war in Ukraine. Lewis is a Pulitzer Prize-winning journalist who reported from Asia and the Middle East for decades. I started by asking him why the U.S. was bombing Laos when it was at war in a different country, Vietnam.

LEWIS SIMONS: Laos is right on the border of North and South Vietnam, now united Vietnam. So the North Vietnamese army was using a good deal of Laotian territory for what they call the Ho Chi Minh Trail, which sounds like it might have been a freeway or a highway, but it wasn't. It was just a jungle path, essentially, that ran in large measure through the mountains and forests of Laos and then into South Vietnam. The North Vietnamese army ran personnel and material down the Ho Chi Minh Trail into the south. And it was - by 1964, it was obvious that they, the Americans, had to do something to interdict the Ho Chi Minh Trail.

KELLY: To try to shut down that passageway.

SIMONS: Precisely.

KELLY: OK.

SIMONS: So President Johnson at the time ordered an operation primarily to interdict the trail and secondarily to attack the indigenous communist force of Laos, the Pathet Lao.

KELLY: I just described - I just listed some of the numbers of how many cluster bombs we're talking. What was the human toll? How many people in Laos died as a result of these cluster munitions?

SIMONS: Ten percent of the population, which at the time was only 3 million. About 200,000 people - Laotian people died. They were civilians and military. Of the civilians, half were children, young children. And mostly they died because they were attracted to these glittery, brightly painted toys, which is pretty much what the cluster bombs look like.

KELLY: To explain, they scatter everywhere. And they're supposed to blow up, but they don't always.

SIMONS: They're supposed...

KELLY: And so what's left is something that a child might pick up and think, oh, what's this?

SIMONS: Correct.

KELLY: Yeah.

SIMONS: Correct. They're supposed to blow up on impact. They're dropped from airplanes. They were dropped from airplanes over Laos. And the fail rate, i.e. the dud rate that did not explode, was somewhere around 45%.

KELLY: The numbers are just so hard to wrap your head around. I wonder if we can take it down to the level of just one person. Tell me about your encounter. You were on a dusty road. You're in this tiny village, and you've - you ran into five boys, including one who told you he was 7 years old. His name was Nai (ph)?

SIMONS: Yes, Nai. Yeah, I had gone from Vientiane, the capital of Laos, to the northern part of the country. The country's only about twice the size of Pennsylvania, by the way - very small, landlocked. And I was there to look at a landmark - Laotian landmark called The Plain of Jars, where hundreds of thousands of prehistoric Laotians were buried in massive stone jars, and it was a main target for the bombings - it and the area directly around it - because that's where the Pathet Lao had their bases. So while I was there, I walked through a tiny, tiny village. Maybe 50 people lived in this little village, and as I was walking with my interpreter along the dirt road through the center of the village, a little group of boys, as you said, five of them - young, all - were running toward me and then stopped. They saw me, the foreigner, very unusual at the time, and I began questioning them.

And this little boy, Nai, was the one I picked out because he was missing one arm from above the elbow, and one eye was completely gone. And I asked him how it happened, and he said that he, like these other boys and like everyone in the village - both children and adults - made a living, so to speak, by digging up unexploded bomblets or cluster bombs. And he had one that he was using his hands - his fingers to scrape out from the dirt, and it blew up in his hand. And it took his left arm and his left eye. And then he turned from me to the others in his gang of kids. They were all about the same age, and most - not all, but most of them had similar wounds - parts of bodies missing, scars on faces, on bellies and that sort of thing. And that's the way it was. And the irony - or the horrible thing, really, is that this is going on to this day.