Everything below comes from gladly living in South Korea in 2015-17; also from being frequently asked lately if I wasn’t afraid to be there. (A hypocrisy in the media’s way of presenting things was not without its role, either.)
tl;dr: A Korean acquaintance told me that if North Korea didn’t develop nuclear weapons USA would have already invaded it.
* South Koreans never speak bad about “the North”.
(Well, at least they never do to foreigners!)
They are disapproving of the regime, of course, but they don’t view North Korea as an enemy. Mostly as the lost half of their country.
(…and with this I don’t mean “the half which has to be taken back”.)
* South Koreans don’t worry about attacks, yes, no matter what the media tell you if I may say so.
People outside asked so many times if everything was alright and if the public was panicking, and every time it felt comical to everyone inside. The reason is that both governments behave the same way (see below) and that neither side is willing to break the equilibrium of many years.
Disclaimer: That was the situation while the undersigned was there. She doesn’t know about recently, but she’s ready to take bets that they worry more about the Trump than about the Bomb.
* The South Korean government prohibits speaking good about the North.
Two years ago an American author was expelled after saying that beer is better in North Korea. http://bit.ly/2yfPtdy
Oh, by the way, three years ago the only parliamentary leftish political party was shut down for alleged ties to the North. http://lat.ms/2xqZZtT