US military power since 1980 has been one of historical significance. The doctrine of rapid manoeuvre in the deep battle space, by elite armies of professional all-volunteer forces has defined the Western Way of War. Professor Tony King contends such an era is over, and the future portends one of positional warfare; endless and indecisive campaigns, in a geography that blends deep, close, and rear, requiring a new approach. The lessons from contemporary conflict, particularly in urban warfare, will challenge the core assumptions on which the West has based its military theology. Heresy? Perhaps. Informed and evidenced analysis? Definitely.