In the worst case scenario, a biological attack on the US could render all humans infertile, or melted into puddles. The advent of modern science, along with the inescapable reprocussions of globalization and imperialism have set the stage for a tense atmosphere. New concerns have arisen in regards to national security, especially in the response to so called "dirty bombs" Weapons that once seemed plausible only in science fiction stories are now being realized.