Professional military cultures differ greatly from service to service and from nation to nation. Yet, they represent an essential component of military effectiveness. How armies, air forces, marine corps, and navies think about war guides their peacetime innovations and determines the patterns of successful or unsuccessful adaptation of war. The military profession is not only the most demanding physically of the professions, it is also the most demanding mentally. But there is another side that military historians and pundits often exclude from their examinations of military culture. That is the portion of the landscape that deals with the physical, physiological, and psychological preparation of military organizations for war. As the Prussian military theorist, Carl von Clausewitz, suggests: “The end for which a soldier is recruited, clothed, armed, and trained, the whole object of his sleeping, eating, drinking, and marching is simply that he should fight at the right place and the right time.”

War places extraordinary demands on the individual. In effect, military organizations require the soldier to remain on the battlefield in an arena of danger where his enemy aims to kill him. They demand that he maintain himself in an environment in which every human instinct suggests that he should leave immediately. Clausewitz brilliantly depicted that terrifying challenge in On War: