ARI SHAPIRO, HOST:
For the past year, as there has been threat and counter-threat between the U.S. and North Korea, the Pentagon has dispatched aircraft carriers to the western Pacific, flown strategic bombers over the Korean Peninsula and laid out battle scenarios. But listen to Defense Secretary Jim Mattis on the way forward when it comes to the standoff over North Korea's nuclear weapons.
(SOUNDBITE OF ARCHIVED RECORDING)
JIM MATTIS: Diplomacy should repose reason on Kim's reckless rhetoric and dangerous provocations.
SHAPIRO: Diplomacy - Mattis has insisted on it. NPR Pentagon correspondent Tom Bowman is here in the studio to talk about this. Hi, Tom.
TOM BOWMAN, BYLINE: Hey, Ari.
SHAPIRO: So Jim Mattis is the defense secretary. But in that clip of tape, he sounds more like the secretary of state in charge of diplomacy. What's going on?
BOWMAN: Well, I think Mattis, as a former general, knows the cost of war more than most. And he said that another war in the Korean Peninsula, in so many words, would be more catastrophic than anything in anyone's living memory. And Mattis in particular over the past number of months, as there's been more heated rhetoric from, let's say, U.N. ambassador Nikki Haley, national security adviser H.R. McMaster - they both talked about time running out for North Korea - Mattis has tried to tamp down that concern, that rhetoric.
I recall there was a missile test once, and people started banging the war drums. And Mattis told reporters at the Pentagon, you know, I don't think this puts us any closer to war. So he's been trying to ease down things.
SHAPIRO: Still, it is the Pentagon's job to prepare for conflict and present the president with military options. What options has the Pentagon presented to President Trump?
BOWMAN: Well, he - they have presented options. Of course they're secret. But not one would be good news of course. The challenge is, how do you take out his nuclear sites? He has thousands of nuclear weapons - or thousands of tunnels, some including nuclear weapons, on - in the peninsula.
And I remember talking with someone in the Obama administration who said, we looked into taking out his nuke sites, command and control in the fading days of the Obama administration. He said, there's only a moderate chance of being successful. That's not the kind of word you want to hear when you're talking about nuclear weapons.
SHAPIRO: And the U.S. has already fought one war on the Korean Peninsula where 50,000 American troops were killed, more even. Millions of Korean troops and civilians died. I hate to ask the question, but what does the Pentagon think a second war would look like?
BOWMAN: Oh, even more horrific. The weapons are much more powerful. The population has grown. People I talk with say you're looking at tens of thousands, maybe hundreds of thousands of casualties on the peninsula, maybe more in Japan if they get dragged in. Of course North Korea also has thousands of artillery and mortars pointed toward the South. So that's a problem of just taking those out as well.
And I just mentioned the tunnels. I know the Army, for example, is training thousands more troops in tunnel warfare to be able to go into these places, go after hidden troops, nuclear weapons or chemical weapons. It'd just be horrific.
SHAPIRO: Today the White House said it expects North Korea to make some moves toward denuclearization before talks begin. There's no indication that the North plans to do that. So what happens next?
BOWMAN: Yeah. We don't know what they were talking about today at the White House. But one officer said the best-case scenario is Kim freezes his programs, and the diplomats just keep talking if not for months and maybe for years. So if this meeting doesn't happen or if it falls apart for whatever reason, you're maybe going back to a very tense square one.
SHAPIRO: NPR Pentagon correspondent Tom Bowman. Thanks, Tom.
BOWMAN: You're welcome, Ari. Transcript provided by NPR, Copyright NPR.