No, in ways I think their should be more done, take Dafur, The Rwanda genocide etc. Now imagine how different those would go if the US, europe etc all sent in a force to stop it and not the timid UN peace keepers (who i feel for but are just not allowed to do much to help).
The problem is people don't really like doing the right thing, unless it helps them. People are always against getting involved in things unless it directly effects them, until after the event has occured... It's why i'm strangely both pro iraq and afghanistan, yes we may have gone in for the wrong reasons but at least we are actually attempting to make the world a little bit better for people (i'm referring to the right to vote, womens rights, democracys not dictorships etc etc etc).
Simply put, the world will be a horrible place for many until those of us who have the luxury of choice choose to use our combined might to stop it. America shouldn't stop, no other country could take its place.