We need peace. We cannot fight evil for peace, just as we cannot fight a war against terror. Peaceful demonstration movements are destroyed by making them fight. Its really easy to do it. Vietnam war for example, or the fight for the right to protest, or the fight against X Y or Z, or Occupy being sucked into fighting for the right to demonstrate in a public place. I am even talking about being proactive and demonstrating against evil and wrongdoing. Even famous campaigners and activists championing for what is good and against political injustices can not lead us to more peace. The only ideology really that I have come across is nonviolence.

I also like the alien threat as incentive for global unity idea - it makes sense in terms of human group psychology (The Other). And I suspect that group psychology may actually make my first paragraph utterly false, as any movement, any group, any collection of humans may not be able to be peaceful. (individuals however could be...)