The DPRK specifically has artillery pointed at South Korea going on 70 years now. Why do you think they haven’t been invaded? The same with Cuba, they defeated the CIA in the bay of pigs. By routing the United States they defacto project power by existing. It’s the same reason Russia was able to park right up next to Cuba (they might still be there idk) obviously Russia is the larger power, but Cuba at the same time is able to say “if you don’t normalize relations, this will be a reoccurring event”