they've been in power for 70+ years - as an article in the "Times" pointed out a couple of weeks ago it's more accurate to see them as a set of Kings or Emperors than Marxists
In general they haven't been involved in a great deal of foreign adventurism - they are keen on killing defectors etc but they haven't the capacity to export much inteh way of mayhem. There is no international set of supporters - such as Al Quaida or ISIS have
They are paranoid - but then they are accurate - everyone IS out to get them. They see what happened to Saddam and Ghaddafi and they think, quite logically, that if they'd had A bombs maybe they wouldn't have finished up dead. They see 8 countries who believe in MAD and they think they can join that club and be more secure than they are now.
They want to hang on to power all right but I don't think they are as crazy as they are portrayed - strip out the rhetoric and their actions are are generally quite careful and considered