Korea could be to Trump what the Berlin Wall was to Reagan. The parallels are there.
I can see North Korea being divvied up into zones of Occupation, like Germany after WWII, China, Russia, the US and South Korea would have their areas to administer.
It’s going to take at least a generation before you can even think about reunifying the country. The people there have to be deprogrammed and slowly brought up to speed to the ways of the South and that won’t happen overnight.