This essay grew out of a short paper I presented to the British Political Studies Association. The more I thought about the subject, the more important it seemed to me. Since nobody else seemed to have examined it -- at least, in the way I thought it ought to be examined -- I felt compelled to do so myself. I hope I have done so competently enough not to have spoiled the field for others better qualified. I by no means offer the book as the last word --- for this will not be written for a long time to come -- but as a first one. I shall be disappointed if it does not lead to further research in this field, however critical of my own standpoint it may prove to be.
I have written it for the general reader rather than for my professional colleagues, though I trust the scholarship will not prove any the worse for that; but this explains why I have cut down the usual apparatus of citations and references, and limited the bibliography.
Colleagues have given me great help and encouragement. I would particularly thank Mr. F. G. Carnell of the Institute of Commonwealth Studies, Oxford; Professor George Fischer of Cornell University; Professor John Lewis, also of Cornell University; my friend, Professor W. J. M. MacKenzie of Manchester University; my old colleague, Mr. A. P. V. Rolo, Senior Lecturer in History at the University of Keele; and, finally, my crony of undergraduate days at Trinity College, Oxford, Brigadier Peter Young, D.S.O., M.C., M.A., of the Royal Military Academy, Sandhurst, who used to beat me in a fascinating kriegspiel which we invented together. All these colleagues read my typescript and offered valuable comments and corrections which have much improved the book.
I must also thank Mr. S. O. Stewart, the Librarian of the University of Keele, and his staff, for the help they have given me in obtaining the very wide range of books and other materials that was necessary to carry out my research.