Disease proves better than most things that the entire world is interconnected, as much as xenophobes would wish otherwise. Ebola isn't really a threat to the USA, but the totally inadequate response the outside world has given it shows just exactly how a deadly pathogen could arise in a place people don't care about for cynical reasons, spread beyond the ability to contain it, then jump the borders and cause mayhem to everyone. All of which could be avoided by ponying up the resources to strengthen the health systems of poor countries like Sierra Leone. As it turns out, the right thing is also the most sensible thing to do, every time, unless all you care about is the next election I guess. But if you care about yourself, your children, your country and our race, then what to do with such problems as poverty, disease, war, or any other is clear.
Ebola is a case in poit refutation of isolationists.