John Barnes
In this near-future novel an apparently leaderless emergent terrorist movement creates organisms that destroy plastic, rubber, and petroleum products: chaos ensues. The directive of the title refers to a 2007 presidential directive designed to insure the continuity of constitutional government in the event of a great disaster. Why the author devotes so much attention to presidential succession is the second biggest mystery in the book (the first being the never-told story of how the terrorist movement started and whether or not it has leaders).
Barnes started with an intriguing premise, but the book degenerates into one of those Turtledove-style SF novels that jump from character to character and from place to place without any rhyme, reason, or transitions. With a couple of exceptions, the characters are hard to distinguish. Ultimately the story wanders off into the weeds. A good editor could probably have made this into a good book, but as published it reads like a first draft.