which mere diplomacy has at its command--in other words by the conflict of armed force. Each State now seeks to bend its enemy's will to its own and to impose its policy upon him. The means of pursuing this policy vary almost indefinitely. But inasmuch as war is essentially the conflict of armed force, the primary object of each belligerent must in all cases be to subdue, and, in the last resort, to destroy the armed forces of the adversary. When that is done all is done that war can do. How to do this most speedily and most effectively is the fundamental problem of war. There is no cut-and-dried solution of the problem, because although war may be considered, as it has been considered above, in the abstract, it is the most concrete of all human arts and, subject to the fundamental principle above enunciated, its particular forms may, and indeed must, vary with the circumstances and conditions of each particular war. Many commentators on war distinguishing, with Clausewitz, between "limited" and "unlimited" war, would further insist that the forms of war must vary with its objects. I cannot follow this distinction, which seems to me to be inconsistent with the fundamental proposition of Clausewitz, to the effect that war is the pursuit of policy by means of the conflict of armed force. If you desire your policy to prevail you must take the best means that are open to you to make it prevail. It is worse than useless to dissipate your energies in the pursuit of any purpose, however important in itself, which does not directly conduce, and conduce better than any other purpose you could pursue, to that paramount end. The only limitation of your efforts that you can tolerate is that they should involve the least expenditure of energy that may be necessary to make your policy prevail. But that is a question of the economics of war; it is not a question of "limited war" or of "war for a limited object." Your sole object is to bend the enemy to your will. That object is essentially an unlimited one, or one that is limited only by the extent of the efforts which the enemy makes to withstand you. The only sure way of attaining this object is to destroy his armed forces. If he submits before this is done it is he that limits the war, not you. Bacon's unimpeachable maxim in this regard is often misinterpreted. "This much is certain," he says, "he that commands the sea is at great liberty and may take as much or as little of the war as he will." That is indisputable, but its postulate is that the belligerent has secured the command of the sea; that is, as I shall show hereafter, that he has subdued, if not destroyed, the armed forces of the enemy afloat. Having done that he may, in a certain sense, take as much or as little of the war as he chooses; but he must always take as much as will compel the enemy to come to terms.