Fourth generation warfare (4GW) is a concept defined in 1989 by a team of American analysts, including William S. Lind, used to describe warfare's return to a decentralized form. In terms of generational modern warfare, the fourth generation signifies the nation states' loss of their monopoly on combat forces, returning in a sense to the uncontrolled combat of pre-modern times. The simplest definition includes any war in which one of the major participants is not a state but rather a violent ideological network.