What’s wrong with human rights discourse is that it’s subject centered, focused on an already empowered subject and the subject’s actions. What gets lost is the other’s right, for instance, the right to protection from abuse. Then what? What if the subject fails to protect or chooses not protect, or does not want to protect, for this or that reason? Then the human right falls flat. It doesn’t mean very much.
Is there not also an obligation to protect? In the case of Syria, this has nothing to do with American exceptionalism, and everything to do with the obligations imposed upon a strong state to protect another suffering people from abuse. This would be the subject’s obligation to protect the other, even in the case when international bodies are hobbled by competing national and geo-strategic interests.
Perhaps the theoretical point is that rights and obligations work in tandem. Obligations activate rights, and rights activate obligations, on the part of a subject and the other.
As always the devil is in the detail as to how this all gets worked out in real time. There are myriad conditions and rules that hem its exercise, some of which go back to the familiar rules of classical just war theory.
The so-called responsibility-to-protect is part of an ongoing, emergent discourse coming out of the UN that dates back to 2005. You can read more about the theory here: http://www.un.org/en/preventgenocide/adviser/responsibility.shtml
For a more sober and critical view with reference to Libya and Syria, see this old column by David Rieff: http://www.nytimes.com/2011/11/08/opinion/r2p-rip.html?pagewanted=all&_r=0
Part of the frustration is that R2P is a moral concept that wants to be legal and political, while the politics gets mired by morality. The R2P might be an imperfect doctrine, but it frames the discussion re: Syria with a little more urgency than might otherwise be the case. It still remains unclear which will cause more damage, an act of intervention against the Assad regime or continuing to do nothing, which I wonder is what happens next.