Miltiadis Michalopoulos This is a very big question. Keegan has written a 600 pages book to answer it. Therefore the answer cant be a simple 'yes" or "no". I think that Clausewitz's axiom still holds its value. Keegan points out that in the 21st century we cant think of war as a means of politics, because this may lead to a nuclear holocaust. But you can see that war still exists and unfortunately it will never end.