Problem is, for that to be possible, you have to get into a situation where those people aren't our enemies. How do you get that? Getting rid of our enemies. How do we get that? There are various ways of doing it but, most involve doing stuff that make people our enemies.

My point? What you're talking about might have been possible (I don't think so though... most people are, in my opinion, assholes by nature regardless of race/religion/politics/gender/whatever) at some point in the distant past but, at this point, the only way of us getting to a point where we have no enemies would mean us being the only ones left. Then again, maybe I'm just too pessimistic...

Anyway, just my $0.02...