There is an angel in the literature of loss who stands at the gate looking back at something beautiful that cannot be recovered. Thomas Wolfe borrowed the image, Milton made it immortal, and if you pay attention to American history with clear eyes, you will feel it too. Not rage, not contempt, but grief. The specific grief of watching something that could have been extraordinary choose, again and again, to be something meaner. This article asks the question that grief eventually forces: if we are the intelligent species, the one with moral reasoning and self-awareness and language, why are we the most catastrophically effective killers on earth, and what does physics have to say about the bill coming due?