In the end Korea were reduced to rubble. With US money, technology and military support, South Korea they became the first world country they are today, with great global economic and political relations. Ont he other hand North Korea were starved of relations and trade, their only helping hand from the red countries and not without a price. Costly weapon and technology trades while the US nipped at them and kept them on edge. Tech moved at a rate a isolated country could not keep up with and China and Russia were happy to drip feed them old outdated crap for big dollar and brownie point when it kept to border disputes.
It's interesting when you examine this view, because it seems to expose the long term flaws in US strategy that we've seen numerous times now, remotely isolate, bully and ostracise - in the hope that one day it'll force change, but the opposite seems to happen, with the target having a tendency to "dig in" for the long haul, rather than yield.
Even with Iran who abandoned their nuclear weapons program, I suspect they were rather cleverly playing the long game - and instead provided expertise to North Korea via a parallel program, to accelerate their efforts, if the US won't act militarily on a nuclear armed North Korea, then I doubt they would on Iran either.