Do the North Koreans have much of a conventional military? Seems like they put most of their eggs in the Nukes basket. Plus, the country as a whole is poor with virtually not infrastructure or manufacturing.
Their only export is “extortion” and giving nukes to terrorist countries.
They have lots of “stuff” but most of it is old stuff and probably not well-maintained. Many of the troops are sent to work in the fields. They don’t have the resources(i.e. gas) for much training.
IIRC their military needs several months to “spin up” to readiness. Any moves like that will raise the ire of the Chinese who see North Korea as a “little brother”.