The concept of “total war” we owe to Karl von Clausewitz, although he never used that word. The word he used was “absolute.” For him it was a philosophical rather than a military expression, and he coined it to clarify a problem arising out of his own experience. Writing as he did in the 1820s, he wondered why the Napoleonic campaigns that had occupied his military career between 1806 and 1815 - swift, brutal, decisive - had differed so greatly from the “cabinet wars” of the eighteenth century on whose lessons he had been brought up. What had changed? Logically, all wars should be “absolute”: there was no reason in the abstract why they should end short of the complete overthrow of one side or the other. In practice, they seldom or never were; at least, not within the rather narrow slice of European history that he took as his database. For him the problem was, not why and when did wars become “absolute” or “total,” but why and when did they not? It was in his search for an answer that he coined the two ideas with which his name is most generally associated: that of “friction,” which distinguished war in practice from “war on paper,” and that of war as “political intercourse with the addition of other means.” The first imposed the internal, the second the external constraints that determined the nature of war in the real world.