I'm not a military expert. But clearly procrastination has not served us well in the past: the situation has continued to deteriorate, and the stakes have grown bigger with every passing year.
This is the last chance saloon. A realistic evaluation of military options should be undertaken, with the objective of neutralizing NK's nuclear capability. If such a strike is possible, it should be accompanied with a warning to the NK regime that any retaliation against the South will result in its own destruction.
There's no safe way to handle this threat. A do nothing policy transforms a smaller risk in the present into a greater risk in the future. The chickens may never come home to roost, but what if they do? Nuclear Fried Chicken.