Theyve had the bomb for a while and south korea still exists and is thriving. I have seen alot of batshit insane talk from them, but no real negative consequences for any other country. So it hasnt really been a negative for anyone. I dont think theyll use it first either because they know theyll be glassed if they do
Now if they didnt have the bomb, i dont think they would have lasted this long. I think the US would have gone and "democratized" them to smithereens a while ago.
Nuclear weapons have a very brief transition from “everything is fine and nothing bad has happened” to “we’re completely fucked.” The fact that nothing has happened yet isn’t very reassuring to me with all the ways things can go wrong. The threat of retaliation certainly puts a damper on a first strike, but there’s always the possibility of a mistake, someone feeling backed into a corner, or not believing the consequences, or just going a little crazy. The more countries that have them, the more likely this becomes.
South Korea has the capability to build nuclear weapons very quickly if needed, they're a nuclear threshold state.