Although there were minuscule signs of hope for a cooling with North Korea this weekend, authoritarianism expert Sarah Kendzior also delivered a sobering reminder that Donald Trump's ignorant fascination with nuclear weapons is longstanding and frightening.

Donald Trump’s sabre-rattling with North Korea is alarming on its own, but his disturbing recent history of demonstrable ignorance and recklessness with regard to nuclear weapons adds an even more terrifying dimension.

As a candidate, Trump had no idea what the “nuclear triad” was — even after it was explained to him by a debate moderator — and reportedly wondered why we cannot use nuclear weapons if we have them. As president-elect, Trump endorsed a nuclear buildup that defies decades of U.S. policy. As president, he reportedly had to ask an aide what the nuclear START Treaty was.

And just this past week, Trump paired his belligerent rhetoric on North Korea with the first-ever combat use of the most powerful non-nuclear bomb in our arsenal.

But authoritarianism expert Sarah Kendzior, whose coverage of Trump has been required reading, points out that Trump’s ignorant obsession with nuclear weapons dates back to 1984. In a sobering segment on MSNBC’s AM Joy, Kendzior noted the volatile cocktail of two unstable world leaders with a tenuous grasp on nuclear diplomacy:

One of the problems is that the rhetoric on North Korea from the U.S. side is very inconsistent. In March, Tillerson announced that diplomacy with North Korea had failed. They began bringing out this idea of a preemptive strike on North Korea. Trump started baiting North Korea with tweets. And of course, North Korea is not going to see those tweets and say, as some American commentators said, ‘Oh, this is a distraction’ or ‘Trump is trying to get out of some sort of domestic crisis or the Russian investigation.’

They are going to see that as an aggressive move. And similarly, Trump is so unsophisticated, he has no actual geopolitical strategy beyond sort of a fetish for aggression, he’ll see things that North Korea has been doing for years, like testing these various military devices, as a direct provocation against the United States, and then he will ratchet up the rhetoric similarly and call for strikes on North Korea and whatnot.

And this is very dangerous, because these are two nuclear powers, and Trump has been obsessed with nuclear weapons since at least 1984, where he proclaimed he had learned everything he needs to know about them within an hour and a half. During the election he said, ‘If we have nukes, why not use them,’ which is in direct contradiction to every nuclear policy we’ve ever had and that most countries have ever had. He’s very erratic, he doesn’t make decisions in a rational way, and so, I unfortunately think that, you know, we should be very worried about where this is going in terms of confrontation between these two regimes.

To put that into perspective, Donald Trump has been obsessed with nuclear weapons for as long as Kim Jong-un has been alive. As Kendzior noted, Trump told an interviewer in 1984, the year Kim Jong-un was born, that he already knew enough about nukes to be an expert negotiator:

He would know what to ask the Russians for, he says. But he would rather not tip his hand publicly. “In the event anything happens with respect to me, I wouldn’t want to make my opinions public,” he says. “I’d rather keep those thoughts to myself or save them for whoever else is chosen . . .

“It’s something that somebody should do that knows how to negotiate and not the kind of representatives that I have seen in the past.”

He could learn about missiles, quickly, he says.

“It would take an hour-and-a-half to learn everything there is to learn about missiles . . . I think I know most of it anyway. You’re talking about just getting updated on a situation . . . You know who really wants me to do this? Roy [Trump mentor Roy Cohn]  . . . I’d do it in a second.”

Now, Trump is locked in a deadly dance with Kim Jong-un, and as Kendzior noted, both men are ill-equipped to conduct public diplomacy on the issue, or to properly interpret the other’s actions.

National Security Advisor H.R. McMaster may be trying to send subtle signals to cool things off, but that is being drowned out by the Trump’s bellowing, and is unlikely to assuage North Korea — and for observers in both countries, and around the world, it is indeed an extremely worrying new reality.