War - what is it good for? The best-selling author of A Philosophy of Walking, Frédéric Gros returns with a book on this highly topical subject.According to one wag, war ?died in Hiroshima? more than half a century ago. And yet it has never gone away.When Russia invaded Ukraine, they said, it's the return of real war, with its atrocities, its horrors, its violence. But what is a real war? Was the violence we had been witnessing in of the war on terror, the implosion of Yugoslavia, Israel's destruction in the Middle East, or the war on women not real war?By calling on the great political philosophers, from Plato to Marx, via Machiavelli and Hobbes, this book attempts to answer this question, along with a series of others: what is a just war? What moral forces are involved in a conflict? Does the state make war, or does war make the state? Finally, after exploring the meanings and stakes of the spectre of ?total? war, he tackles the ultimate question: why war?