Africa does not "have a government and a military," it has lots of different governments and militaries.
Intervention.
Now, seeing as I'm not an expert on military interventions, I would defer to people who knew more about these things than I do. I like Michael O'Hanlon's idea here, for instance:
http://www.tnr.com/darfur/darfur.mhtml
(The New Republic has done some of the best writing, editorializing, and reporting on the Darfur genocide that I have encountered.)
I do know that the US and its allies have helped stop genocides before, and done a pretty goddam good job of it.
But that was in the Balkans, which is just a bastion of peace and civility. Unlike that horribly savage and unsalvageable Africa.
(don't ask me why I'm arguing with someone who thinks that lowering the murder rate in South Africa will somehow stop the genocide in Sudan, on the other side of the fucking continent)