A small portion of us may be Warmongers, but Fear can be just as dangerous.
I have stressed this in a few other posts, but as far back as you can go have you ever seen a Alien movie that wasn't violent or made to scare people? "Paul and Close encounters of the 3rd kind are exceptions" When all of a sudden ships start to show in our sky's that is the first thing people will think of, is "We are being invaded we need to protect our selfs" even if the Gov or a ET stated there was no ill intent people would still panic and that alone is enough to cause mayhem.
It only takes a spark to start a forest fire.....