Give them a taste of capitalism they will change their tune.
First, they will not believe it, then they will revert to their programming that it is just a trick of the evil capitalists. Imagine being 60 years old and knowing nothing but the reign of the Kims, with all that implies. No outside media, no outside culture, no outside influences (to have them is to risk death). It would require all but a very few of them to discard every belief they have ever held, fostered by a State that controlled everything they saw, read, or had.
They would assume that any other State would do the same, only with their stuff, and whether or not they would believe it remains questionable. Then, too, there would be the problems of industrial and other espionage performed on behalf of the Russians and the Chinese.