Sharpton said he wouldn't choose sides in the conflict
Then who the heck does he want us to stop? No, no, don't pick sides, then you might have to take a STAND for something and not be able to flip flop so easy.
This is the key point. Pres. Bush has taken sides, and I presume Sharpton is loath to be on the same side. So instead he talks about sending peacekeepers. I guess we do too, but the problem is that:
a. There is no peace to keep
b. The existing leadership is the problem
Should we be the solution and overthrow the existing government? I'm unsure, but lean towards yes if and only if the best intelligence indicates that the task will be easy and that we can quickly exit afterwards.
As to whether it is our responsibility, it is true that the US founded Liberia, but that was an awful long time ago. So we don't have as much responsibility as, for example, the French have in Ivory Coast. Tough call.