I do believe that, somewhere out there, there are aliens. But if there are, then there is a guaranteed fact that there is a resource/power-seeking species out there that crushes all planets in their way. There would also be a species who's home-planet is dying and will either join or crush us. This would also mean that there are diplomatic species out there that would be willing to allow trade rights, and idea exchanges, and even join our society, or let us join their's.