What is the world supposed to do about (rogue) governments brutality?

Difficult leaders are one thing but governments brutality is totally of a different level.

How does these bunch of people can become the government in the first place anyway? Is there a problem with their education, their culture, what is it?

Does the world need to interfere (I think so), and how?

Kofi Anan apologized for the UN dismal performance in handling Rwanda. But now, Darfur, then what? Does Ban Ki Moon want to just apologize afterwards?

Is the world supposed to just endure and wait until they lose power or die?