Aggressor was an attempt by the US armed forces to make war-games more realistic by having an adversary that behaved and looked differently then those being trained (in other words, not just splitting a group in two). A completely fictional background was developed for Aggressor including political philosophy, language (actually esperanto) and uniforms. 4 basic manuals were published with updates over the years: * FM30-101: Aggressor the Maneuver Enemy * FM30-102: Handbook on Aggressor Military Forces * FM30-103: Aggressor Order of Battle * FM30-104: Aggressor Representation