In an era of broad and perhaps profound change, new theories and concepts are to be welcomed rather than shunned. However, before they are fully embraced, they need to be tested rigorously, for the cost of implementing a false theory and developing operational and strategic concepts around it can be greater than remaining wedded to an older, but sounder one. The theory of Fourth Generation War (4GW) is a perfect example. Were we to embrace this theory, a loose collection of ideas that does not hold up to close scrutiny, the price we might pay in a future conflict could be high indeed. In this monograph, Dr. Antulio J. Echevarria II provides a critique of the theory of 4GW, examining its faulty assumptions and the problems in its logic. by subscribing to this bankrupt theory. If their aim is truly to create positive change, then they- and we-would be better off jettisoning the theory and retaining the traditional concept of insurgency, while modifying it to include the greater mobility and access afforded...