"Human rights violations" are a problem the world over, but in order to get anywhere on the subject you first have to decide what constitutes a "right." By the United Nation's definition, human rights are: "inalienable fundamental rights to which a person is inherently entitled simply because she or he is a human being. Human rights are thus conceived as universal (applicable everywhere) and egalitarian (the same for everyone). These rights may exist as natural rights or as legal rights, in both national and international law."
That means you're born with them and you don't have tor earn them.
So, what are these rights?
Something like these:
- Life (people have the right to not be killed arbitrarily by other people.)
- Torture (people have the right to no be tortured)
- Slavery (people have the right to not be slaves)
- Fair trial (when accused of something, people have the right to a trial that is conducted in a fair way)
- Speech (people have the right to speak freely and without censorship.)
- Thought, conscience, religion (people have the right to think what they want, have their own morals, and practice their own religions.)
This is the main list. There are lots of other "rights" various groups would add in there, but it's hard to argue against the six above.
As far as a "threat to the world," that bit is debatable. The threat is mainly a moral one. The threat is mostly to the people whose rights are being violated (unless you consider the greater threat to our human morality.) For instance, look at China. Though they are improving, the state can censor your speech, take away your ability to have opposing political views, use prisoners for slave labor, and execute you should you do something wrong (China is BIG on capital punishment.) Despite these violations, China's economy is booming. People are still having babies there, and we buy tons of their products. The violations themselves aren't a threat to the world, only a downer.
I don't mean to sound glib, it's just that human rights violations have been going on since the beginning of time. That doens't make them right, and it doesn't mean we shouldn't work toward fixing the situation, only that when many people around the world can't even get clean drinking water the idea of going after other nations for violations gets a lower priority. Horrible human rights violations in one palce (such as what happened in Cambodia, Rwanda, or what's happening in Syria) can destabalize a region as people flee and cause all sorts of problems for the surrounding area. These are a threat indeed, but the real issue is caused by the refugees and the inability to deal with so many people flooding out of the nation. For instance, Cambodia could have kept up with the "killing fields" for a lot longer had they not attempted to invade Vietnam, forcing a war. Nobody was stepping up to stop them.
So what does get done about the situation? Not much. There is a lot of talk and treaties, but (of course) nations that want to squash people's rights don't sign them. Economic sanctions can work but don't get used much for fear of messing up the economy. Military intervention sometimes helps (Bosnia) but usually doesn't (Somalia.) Most of the time nations wait for the worst to be over and then come in to help clean up the mess (Rwanda.) To beat up a bully on the other side of the world you need to find a bigger bully, pay him, fly him over there, and deal with his victims. Nobody wants the cost.