Barton Gellman

Stuxnet, a computer worm reportedly developed by the United States and Israel that destroyed Iranian nuclear centrifuges in attacks in 2009 and 2010, is often cited as the most dramatic use of a cyber weapon.

By irreducibly complex I mean a single system composed of several well-matched, interacting parts that contribute to the basic function, wherein the removal of any one of the parts causes the system to effectively cease functioning.