Let's content ourselves with worrying about the future of human life. Other forms of life can fend for themselves, and probably exist on countless other planets as well. We have enough on our plates to try and keep ourselves alive, which I feel is certainly a valid goal for humanity. If we possess weapons that are capable of ending all human life, that is an important watershed event, and not a good one.

To put this in perspective, I once asked a class of 20-year-olds what people worried a lot about in the 60s. What kept people up at night in the 60s, more than anything else? They had absolutely no idea. Food for thought.