War is . . . an act of force to compel our enemy to do our will. . . . Attached to force are certain self-imposed, imperceptible limitations hardly worth mentioning, known as international law and custom, but they scarcely weaken it. Force—that is, physical force, for moral force has no existence save as expressed in the state and the law—is thus the means of war; to impose our will on the enemy is its object.
