From John Keegan’s A History of Warfare:
In short, it is at the cultural level that Clausewitz’s answer to his question, What is war?, is defective. That is not altogether surprising. We all find it difficult to stand far enough outside our own culture to perceive how it makes us, as individuals, what we are. Modern Westerners, with their commitment to the creed of individuality, find the difficulty as acute as others elsewhere have. Clausewitz was a man of his times, a child of the Enlightenment, a contemporary of the German Romantics, an intellectual, a practical reformer, a man of action, a critic of his society and a passionate believer in the necessity for it to change. He was a keen observer of the present and a devotee of the future. Where he failed was in seeing how deeply rooted he was in his own past, the past of the professional officer class of a centralised European state. Had his mind been furnished with just one extra intellectual dimension – and it was already a very sophisticated mind indeed – he might have been able to perceive that war embraces much more than politics: that it is always an expression of culture, often a determinant of cultural forms, in some societies the culture itself.