Not sure whether to put this one under chat, ASBs or Books, but here goes. A number of Scifi authors, including Alien Dean Foster and to a lesser extent Harry Turtledove, together with several movies (Independence Day for one) have humanity more or less uniting to fight a common enemy - putting behind either entirely or to varying degrees the centuries of religious and racial conflict preceding "the event". How likely is this? Personally I find it very hard to credit, unless the aliens were out to completely exterminate humanity - unfortunately I feel the hatreds and resentments in some cases are just too deep. Any thoughts?