Answer to title question: Nope. Not as long as the country’s capital and industrial heart is within range of the North’s 250,000 artillery tubes, rails and launchers. Which it is. The minute they go back to war, Seoul goes up in sheets of fire - without needing a nuke to do the job at all. This is why there’s never been a permanent resolution to the Korean War, only an armistice - it’s a Mexican standoff.
SK has had 50 years to relocate the people and much infrastructure from Seoul southward out of artillery range. No excuse.