In the past, posits Christopher Coker, wars were all-encompassing; they were a test not only of individual bravery, but of an entire community's will to survive.
In the West today, in contrast, wars are tools of foreign policy, not intrinsic to the values of a society - they are instrumental rather than existential.
The clash between these two ""cultures of war"" can be seen starkly in the recent struggle in Afghanistan.
In this text, Coker offers both a history of martial cultures and an analysis of how these are now changing.
He locates the origins of the Western way of war in ancient Greece: for example, in the heroic ideals of Homer's Iliad.
He then traces the development of this warrior spirit, moving from Rome's systemization of violence to encounters with such alternative ways of war as Sun Tzu's, the Islamic tradition, and Japan's kamikaze actions during World War II.
This trajectory, he finds, ends in a crucial contemporary fault line: for the first time in history, war is no longer considered humankind's most revealing behaviour.