A Can of Man

It's really not that simple MontyB.
The amount of communications and resources necessary to conduct an uprising is actually enormous. It's not a coincidence that the main catalysts (at least in the very beginning) to America's independence were wealthy landowners.
If you have a population that is mostly poor, uneducated and unable to communicate with one another due to the presence of an effective secret police, uprisings will be destroyed before they can even start. Any move to attempt to oppose those in power can mean brutal death not just for you, but for your entire family.
I can't tell you specifics (because a lot of information is classified) but you may not realize just how bad the extent of brutality is in North Korea. I would imagine Iran has similar kinds of apparatus set in its country. It is insane. I think Phoenix probably knows some of this stuff about Iran, which is why he feels so strongly about the need for the Mullahs to be overthrown. Though Korea is a 2nd when it comes to me, the things I know about North Korea make me feel very strongly that Kim Jong-il should not be allowed to have a natural death.
The people making stands and stuff is most often a case where the rulers are actually not entirely oppressive. Oppressive, yes, but absolute amateurs compared to North Korea or Iran.

And on another note... all this thing about us first world people going on about how we should forgive these tyrants... we don't have a right to forgive them. Only each and every person who has suffered a great deal (suffering of unspeakable levels) can forgive. But if you ever found out what they went through, to forgive would be a crime to not only the current generation, but future generations.
As for people who demonstrate and talk about "standing up" etc. in safe countries like the US, I say why don't they go over to these countries and help establish a network to get these people to communicate with one another? There are operations like these in other places (again, can't go into specifics) but even with their help, uprisings are as good as group suicide that ultimately leads to nothing.
Have you ever heard of any uprisings in North Korea? I'd be very surprised if you have. But then again, this isn't really something I'm at liberty to say (though if you google hard enough you may find your answer... you know some people can't shut up).