Paul Kimball and I are having a friendly blog-war over the human dimension of extraterrestrial contact.
Does anybody really think that the global reaction would be one of universal joy, where people who have hated each other for centuries would suddenly toss down their weapons and embrace each other as brothers and sisters? I don't.
Neither do I. If anything, I think we'd experience a fierce (if relatively brief) upsurge of violence between and among certain cultures as the new "threat" was digested.
That said, I still advocate disseminating knowledge of an ET presence. As I comment on Paul's blog, The Other Side of Truth:
Looking at this from an existential perspective, I'm convinced that, on some deep level, we need this experience. I'm not pretending to suggest it wouldn't be destabilizing. But I think the human psyche could weather this -- and maybe even come out a bit more "cosmic" in the process.
The ecological clock is ticking. We need to mutate if we're to survive in any meaningful sense of the word. Knowledge of ET visitation could play an important role in lifting the veil of duality that we've laboriously imposed on the universe.