thank you for reply. I read some articles(written in english) made from Korea's press. I use Korea herald site when i want to know about Northkorea's situation. sometimes i would watch documentaries covering Northkorea problems. (BBC docu was good for me to understand their life specifically, you can see it on yutube or other ucc sites) . i absolutely agree with you that most of countries that have maintained totalitarian regime are quite weak against world's change and the changing public. i think, the reason Northkroean can't resist against it's cruel goverment is that they have no power to collapse two dictators. (Most of Northkoreans have been suffered from starvation)
Where did you read that North Korea was worried about revolution? I'd like to read that. Everything I've ever heard about North Korea (from apparent scholars of the country and diplomats) seems to point to the regime having a firm and long lasting grip on power expected to last at least another generation. With the only real point of instability being internally within the ruling elites.
I've heard it said though that in the past defectors claimed the people really did believe the government's propaganda, but recent defectors are claiming that the effect is beginning to erode.
Apparently few people expected Egypt or Tunisia to ever go the way it has recently, so the same could be said of North Korea. Many totalitarian regimes are hallow and one sign of weakness (such as in the Middle East now or in Eastern Europe twenty years ago) and the whole edifice would crumble. Can this be said of North Korea, I'm not sure. I'd hazard to guess that more than Iran last year and China during the Tiananmen Square protests twenty years ago, the North Korean regime is willing to violently crush a popular uprising.