The viciousness of the North Korean regime towards its people requires a response by the international community because its actions offend the conscience. While some will argue North Korea is not alone in requiring the international community's condemnation, the difference is significant.
Syria is in the middle of a civil war while the North Korean regime is in a non-declared war against its own people minus evidence of opposition from the unwitting victims of the regime. Sadly, aside from moral condemnation there is little that can be done to end the brutality either regime.
The Ukraine is another state on the brink of civil war depending on what "experts" one believes! The list of at risk nations grows daily - from Iraq to Somalia, from Darfur to the CARepublic. It's easy to forget that the US had to endure a 200 year British "occupation," a revolutionary war which split the colonists, followed by a civil war. The road to democracy is a bumpy ride as French history illustrates!
Nation-states are like children, the learning curve varies even with siblings let alone strangers! We should keep this in mind before we try to muck around to make things better... But anyone who is a parent knows how easy it is the say "stay out of it" and how hard it is to avoid interfering. The problem is that emerging nations are like 3 year olds - they live for the moment. There is no long term plan!
Twenty years ago the Pol Pot regime in Cambodia was cited by the UN for crimes against humanity. Sadly history repetes itself too often. But "breaking the silence" is the first step to bringing about justice.