The latest aggression from North Korea this week builds upon years of mounting tension and is now rising to a threat of war. The fact is, the war never ended. We recently visited South Korea to hear from those who have lived under North Korea's threat for more than 60 years and have been convinced for some time that the dictator does have nuclear weaponry.
Rick Lamb: That is their northern boundary. This is our southern boundary.
We're at the world's most dangerous border.
Rick Lamb: Probably the most fortified position on planet Earth.
Rick Lamb led a U.S. military Quick Reaction Force during the last firefight here involving Americans. It was 1984, and a defector dashed across the border to South Korea. U.S. troops opened fire on North Korean troops that followed.
Sharyl Attkisson: You said it escalated very quickly?
Rick Lamb: Oh god, yeah within ten minutes. We basically killed six, we captured six, and as we were taking them captive, we got a call from CP Seoul who said: "stop, pull back, give them an opportunity to save face, let them get their wounded and their dead out of South Korea."
Sharyl Attkisson: Is that the key with the relationship over the past few decades, the ability to dial back when there is some sort of incident?
Rick Lamb: That is our number one course action.
Today's question is just how to dial back in the face of North Korea's test of a supposed hydrogen bomb, and the launch of a new intercontinental ballistic missile.
Nikki Haley: His abusive use of missiles and his nuclear threats show that he is begging for war.
James Mattis: Any threat to the United States and its territories, including Guam or our allies, will be met with a massive military response, both effective and overwhelming. Sharyl: Lamb says today nerves are on edge.
Rick Lamb: The Kaesong heights behind me, 10,000 pieces of artillery dug into granite that can range 1/2 of the population of Korea. 50 million people in Korea, 25 million of them live in Seoul and they're under this cannon fire. So going to war here, nobody wants it.
Sharyl Attkisson: Do you agree times are growing more dangerous in the last year or two?
Rick Lamb: You know you can feel the tension, it's palpable. It's been escalating probably since about 2010.
Tension is growing with North Korea's aggressive provocative missile test schedule. With 20 launches so far in 2017, this could be a record year.
Here at the demilitarized zone between North and South Korea, it's easy to understand why a hostile North Korea with nuclear weapons would be seen as a game changer. But some here in South Korea have told us they think it's the U.S. that has more to worry about. Last Fourth of July, North Korea fired off its first intercontinental ballistic missile or ICBM, claiming it could reach "anywhere in the world," putting the U.S. within possible range of a nuclear strike.
Kim Byeong-gi: They're probably continuing military provocation because they want to disrupt the alliance between the U.S. and South Korea before the alliance gets stronger.
Congressman Kim Byeong-gi serves on the defense and intelligence committees of the Korean national assembly.
Kim Byeong-gi: I'm in a position where I can acquire more information on North Korea than others. Considering the pace of nuclear and missile development in North Korea, I'm concerned that it's much faster than I had thought.
Sharyl Attkisson: Do you think there are other potential victims of nuclear weapons in North Korea, such as Japan and even the United States?
Kim Byeong-gi: It's very clear that Japan and United States are not free from the threat of North Korea.
And by most accounts, the hostile dictatorship of North Korea is poised to become more dangerous, more threatening than ever towards its South Korean neighbors, who are going about their daily lives. Hye-hoon Lee leads South Korea's opposition party and agrees on the status of North Korea's weapons development.
Sharyl Attkisson: Do you think North Korea has nuclear weapons already?
Hye-hoon Lee: I think so. I think a weapon, a nuclear weapon, is almost done.
Sharyl Atkisson: Do you think, in your lifetime, you will see North Korea attempt some sort of attack on South Korea again?
Hye-hoon Lee: Well, I hope not, but the possibility that they will attack us, and the threat that they will attack us, is not good.
Sharyl Attkisson: Do you think North Korea already has nuclear weapons?
Ra Jong-yil: Yes, that is the general opinion.
Political science professor Ra Jong-yil was a campaign adviser to South Korea president Moon Jae-in who was elected in May.
Sharyl Atkisson: What sorts of weapons might they have?
Ra Jong-yil: Nuclear weapons basically, and I think they are in the process of making them smaller to fit them into nuclear missiles.
Professor Ra told us he'd recently met with a group of European diplomats who'd spent three days in North Korea talking to the Kim regime and said there may be room for backchannel communications to defuse tensions.
Ra Jong-yil: Basically, the North Koreans, they would like to have talks with the United States and South Korea, they are open for talks. They are expecting, the US or South Korea to take the initiative in starting, starting a talk. One of them told me if North Korea has any message to the United States it is "ICBM".
Sharyl Atkisson: ICBM?
Sharyl Attkisson: You think they were being threatening or joking?
Ra Jong-yil: Half and half, I think.