Pakistan is a current nuclear threat and has a long and current record of conflict and current small border skirmishes with India.
Iran will be a nuclear threat at some point and has a long recent history of hot wars, proxy wars, huge support for terrorists, etc.
North Korea has nukes now but effectively is not a threat to anyone. They haven’t been in a war, fought a proxy war somewhere else, support terrorism to any large extent, and besides some random acts of a nuisance or criminal nature (like kidnappings and missile overflights) hasn’t really been a threat to anyone. They’re effectively the Cuba of Asia, ripe for more democratic governance but otherwise better left alone.