Serious question, because everyone seems to be talking about how NK doesn't have means to deliver a nuclear device over to SK. If they can hit Seoul with conventional weapons, why couldn't they retrofit some of that tech to carry a nuclear bomb?
From an article on NPR (http://www.npr.org/2013/01/28/170473476/north-koreas-rhetori...):
"The toughest technology in the nuclear world is to shrink a nuclear weapon down to something that is light enough to fit on a warhead and that can detonate at the right place and so forth."
