He’d be smarter to simply rely on subversion.
Kim has a ready made legion of supporters in the American educational system. Particularly at the universities where the professors are guaranteed to side with North Korea in any conflict against the US.
The “more up his sleeve” is almost certainly cyber warfare. Not against military targets, but softer targets like banks, mercantile exchanges, electrical distribution networks, municipal governments, and other civilian installations.
Wal-Mart is not exempt from this kind of attack.
They will not side with north korea very long. they will be dead