1976 was a vintage year for Clausewitzian studies. No less than three major works were published; Raymond Aron's two volume study Penser la Guerre, Peter Paret's Clausewitz and the State and a new English translation of Vom Kriege by Michael Howard and Peter Paret. In curious way all three works are complementary; we have a modernized text complete with introductory essays by Michael Howard, Peter Paret and Bernard Brodie, together with a reader's guide; a full biographical study placing Glausewitz in his intellectual and political milieux; and an extensive critical analysis of his thought with an attempt at relating it to the modern world. There is no longer any excuse for Glausewitz to be “well-known, but little read”. Taken together they make an impressive oeuvre, of interest to the historian, whether of ideas or of war and to the strategic theorist. One thing all these writers have in common is their conviction that Vom Kriege has a continuing relevance to the study of war. It is with this, in particular the relation between theory and practice, that this article is primarily concerned. Consequently, it is first to Aron, who devotes most of his study to this question, that I turn.