Looking back over the present study, particularly its latter chapters, it sometimes appears that the logistic aspect of war is nothing but an endless series of difficulties succeeding each other. Problems constantly appear, grow, merge, are handed forward and backward, are solved and dissolved only to reappear in a different guise. In face of this kaleidoscopic array of obstacles that a serious study of logistics brings to light, one sometimes wonders how armies managed to move at all, how campaigns were waged, and victories occasionally won.

That all warfare consists of an endless series of difficulties, things that go wrong, is a commonplace, and is precisely what Clausewitz meant when talking about the ‘friction’ of war. It is therefore surprising that the vast majority of books on military history manage to pay lip service to this concept and yet avoid making a serious study of it. Hundreds of books on strategy and tactics have been written for every one on logistics, and even the relatively few authors who have bothered to investigate this admittedly unexciting aspect of war have usually done so on the basis of a few preconceived ideas rather than on a careful examination of the evidence. This lack of regard is in spite - or perhaps because - of the fact that logistics make up as much as nine tenths of the business of war, and that the mathematical problems involved in calculating the movements and supply of armies are, to quote Napoleon, not unworthy of a Leibnitz or a Newton. As a great modern soldier has said: