Chicken Run

Fear of widespread germ attacks has made some on the right feel justified in considering the unimaginable. "Biological weapons can kill more people ounce for ounce than a nuclear weapon," said Jack Spencer, a defense analyst at the conservative Heritage Foundation, which feeds the administration many of its policy ideas. "You need to be able to deter someone. If the only reasonable threat is nuclear, then you can't keep that off the table."

Additional reporting: Ariston-Lisabeth Anderson, Meritxell Mir, and Sarah Park