We definitely won't live in peace forever. Whether it be greedy leaders, or unfortunate accidents, there will never be true peace. All the leaders in all of the world could sign one big peace treaty together and there still wont be peace. Even countries that we(USA) have treaties with still aren't peaceful for each other. I guarantee you that if you do some digging you'll find that even that the "peace" exists, we are still sending in task forces, and spies, and agents within the same area, unconfirmed by the country on the opposite side of that peace treaty.