"Fear mostly," River said after a long moment. "That and humans can be quite... blind to things they don't want to see."

She had a pot of tea handy and moved to pour a cup for herself and then one for Peter in case he wanted it as she continued talking.

"But then not everyone CAN see what you just described until its too late. The people who can are the ones who try to do something. Not nations, nations never stopped a war, but men and women. And while one man can save world, those men are very few and far between."