90% of North Koreas trade is with China. They could shut down lil Fat Boy in a heartbeat. The “solution” to the NK problem is and always has been economic sanctions by Beijing.
If China were smart, they’d take this opportunity to oust Fat Boy and take over NK and declare peace within the region.
The solution to the problem would be a Chinese engineered “unfortunate aircraft accident” that takes out Kim and whatever remains of his dynasty. Then a hand selected, by Beijing, replacement put in place. The regime in China need only look back to their country’s history with family dynasties, most recently with how Madame Mao and the Gang of Four were dealt with, to see what needs to be done.