Transcript for War of words between President Trump, Kim Jong Un escalates

Thank you. Joining me to discuss the escalating tensions with north Korea, retired general James cartwright. And Evan osnos of "The new Yorker." I want to start with you, general cartwright. Americans are clearly nervous. Concerned about president trump's judgment in this. How close do you think we are to a military confrontation? Is all this making it harder? My sense is that the tepgss are as high as they have been in anybody's recollection. We're really at a dangerous point. The likelihood of a direct confrontation is probably not that high. That's not the way North Korea operates. They tend to pick off people who are out on their own, think Pueblo, any number of incidents we have had with them. A direct confrontation, they can't win. More likely it will be something we stumble into. Somebody misinterprets an action. You have two forces standing against each other on their. Pi toes. Ready to go. We have provocations. Kim Jong-un feeling personally insulted. Everything he has said he would do, I will test a hydrogen bomb, I will send an icbm test, he's done. So why wouldn't he test a high drone general bomb? I think the likelihood is there that he'll test a bomb. At some point. It's time to state very clearly, flying missiles over our allies, endangering other populations is unacceptable and has to stop. And there are con quens for that. They're probably more along the line of we're going to engage those activities. Use our capabilities in missile defense to address those issues. A direct confrontation on their soil is not likely. Evan, you spent so much time in North Korea. You talked to a lot of officials. How do you think they view what is going on? Do you agree he'll not go to war? Well, by the standards of dictatorship, Kim Jong-un is extraordinarily worried about perceptions. Until recently, the north Korean officials had told me they were aware of the fact that president trump had not personalized this dispute. They thought that meant there was an opportunity, a possibility for diplomatic negotiation. The risk of personalizing it suggests that that may no longer be possible. Would you also think he would test a hydrogen bomb? I think he's indicated he is willing to do extraordinarily provocative things. We need to be prepared for that. I asked the secretary about that. He said he wouldn't talk about it. Ifhey do that, there's very serious consequences to something like that. We haven't done an atmospheric test in decade. How would we respond? It would have to be militarily, wouldn't it? Guessing what we would do in the future is hard. The time right now should be spent on declaring what is not acceptable. You're not going the fly over Japan. Not going to fly over south Korea. So he's doing the right thing? You have to declare those things to make sure people understand. When we first started with the north Koreans, they were launching over the top of Japan. We said, one, you have to tell us when you're going launch. Two, where that's going to go, what areas it's going to come down in. They, over time, came to that. Two or three laumpls before they got the idea. We have to start now to declare that space. If we don't, then it's very difficult as you get further down the road, if we act, how it will be sbrep receiinterpreted? We don't know. How we view each other is a problem. We don't know. Tremendous gap between perception. If there's one lesson on I took away from the trump, as much as we don't understand what Kim Jong-un does, the north K Koreans don't understand president trump. There's a strong view on the national security community we're ready to have some kind of engagement. Thank you both so much. Fantastic article, Evan. When we come back,

This transcript has been automatically generated and may not be 100% accurate.