Much like it is absurd to pretend that Trump has had no effect on RoK/DPRK relations. He has given them common ground. The DPRK has always operated from the notion that the US cares nothing about them and could launch an attack at any time intending to slaughter them out of hand. Until Trump the RoK has operated from the notion that the US would not do such a thing since it would also lead to millions dead in South Korea and a huge hit to GWP that would hurt the US economy. Trump has made perfectly clear that the US could, at any time, elect a president that couldn't care less about South Korean casualties who is also so economically illiterate as to not understand the consequences to the US economy.
So now the RoK and DPRK have a mutual problem of survival proportions and they have to find a way out. That's why they are talking, and what they are talking about.
I'm certainly not saying that Trump is
irrelevant, but rather than it's odd how much the Korean problem is viewed through an American lens. As in, even in Australia, it's viewed through an American lens, as if the problem is that now North Korean missiles can deliver a nuclear warhead to one particular foreign country instead of the other foreign countries to which it could already do the same. Again, that's not to deny the importance of the US in this dispute, it's to say that the frame of reference seems off. I think it's probably the spectacle of Trump that drives this, more than his actual direct impact, which I think is relatively minimal in a marginal sense (i.e. compared to any other US leader faced with the prospect of a nuclear-capable North Korea). After all, when Trump tweets that he has nuclear weapons and is not afraid to use them, that's actually one of his more conventional policy positions, because to my understanding it's entirely in line with US foreign policy since the end of the Korean War. It's the mode of communication that's unique.
So I'm sceptical of the notion that the big agent of change in the Korean dispute is Trump, and suspect the tendency to focus on him obscures potentially more convincing reasons for change (if indeed there has actually been any actual change, as opposed to a return to a different spot along a familiar cycle).
I suppose there's an element of laziness in that complaint; if I looked hard I could probably find those more convincing reasons, without asking the media I typically consume to feed them to me, but it would be nice if they could at least
entertain some non-Trump-centric explanations for the current situation.
consider this: it is much harder to have the NK propaganda machinery running when Al Gore is calling for world peace, otoh it is very easy to rail up your own citiziens when the "most powerful" man in western politics quite literally declares you as part of "the axis of evil".
Is it though? How much does reality really limit North Korean propaganda? Has it really changed that much since Obama was in office? Didn't North Korea essentially treat the US the same way back then, albeit with a bit less theatre?
I don't think perception is unimportant, and to a large extent I suppose it doesn't matter whether there has been an
actual departure from longstanding US policy, if there is a
perceived departure.