re: Obama, Africa and war
To find out how much of that is sheer gas would take a lot of work, including looking up the original legislation and tracking the appropriated money to see if any of it actually accomplished anything. Without those details, I have to reserve judgment on most of this.
The U.N. is utterly useless in any situation involving even minimal military force. As peacekeepers, you could do it more cheaply and just as effectively with cardboard cutouts of soldiers. Despite accumulated evidence on three continents, somehow this just doesn't sink in.
Now, when it comes to humanitarian and health things, they do a pretty decent job in places, and a role in that kind of work would be fine.