Starving NK can definitely be arranged. First you make sure they cannot trade, then you wait for things to get bad. The NK economy will not thrive and almost certainly will go south. As to how much starvation is needed for regime change, I don't know, but unlike Clinton and Bush, Trump can be believed that he'll not buckle, and that he'll provide no food aid.
I'm kinda trolling but not really.
It occurred to me a week or two ago that he, of all people, might actually be able to switch US to the Metric System and make it stick.
I think the difference between Trump and most other politicians is not the level of BS, but that he's always winking. I've often heard that his supporters don't take him literally, but take him seriously, and his haters take him literally, but not seriously. I think there's a lot of truth to that, and despite the carpet bombing of propaganda and hatred from the MSM won't be able to cover up forever that he's accomplished some good things.
President Trump evidently knew this and threatened to do this. It helps that China is so dependent on trade with the US, which means that DJT could threaten China's pocket book as well (which he did). China cooperated with the US, and Kim folded.
It's that simple.
Sure, Kim was in a strong position but for this.