SK have let the US handle the NK problem for far too long. It's time for the US to step back and let it be dealt with by people who actually understand the issues.
Not sure SK will be the best to handle NK. And I'm not sure it's simply a matter of "understanding the issues".
But my point was that during Obama, at least there was some distancing or not so overt threats. More making sure that NK wouldn't be given free rein. With Trump it's (at least so far) empty dangerous threats. It can only lead to war or NK defying the US more and more without consequences. Sometimes it is best to let the dragon sleep and undermine it.