In what ways is this pressure exerted? Partly through the stomach, partly through the pocket, and partly through the spirit. In the “good old days” more forcible physical measures were practised, burning, pillage, and rapine. But in the present age the wholesale and avowed use of such persuasive aids is barred by the ethical code of nations――and press publicity, though, as the last war showed, still indulged in sporadically with or without the specious excuse of “reprisals.” But if the international conscience is too tender to permit this direct violence, it swallows its qualms where the people’s will to resist is undermined by the indirect method of wholesale starvation. Deprive individuals of food and there is an outcry, cut off the food supply of a nation and the moral sense of the world is undisturbed. Thus the naval weapon is pre-eminently the means of applying “stomach” pressure, because its blockade is indirect instead of direct, general instead of particular. As nothing more surely undermines moral than starvation, a blockade would seem obviously the best means to gain the moral objective were it not for two grave disadvantages. First, it can only be successful where the enemy country is not self-supporting, and can be entirely surrounded――or at any rate its supplies from outside effectively intercepted. Second, it is slow to take effect, and so imposes a strain on the resources of the blockading country. Pressure through “the pocket” can be exerted directly by levies, confiscation, or seizure of customs――which require a military occupation――and indirectly by the general dislocation of business and the stoppage of the enemy’s commerce. Above all, as the military forces of a modern nation are but the wheels of the car of war, dependent for their driving power on the engine――the nation’s industrial resources――it follows that a breakdown in the engine or in the transmission――the means of transport and communication――will inevitably render the military forces immobile and powerless. Just as the engine and transmission of an automobile, because of the intricacy and delicacy of their joints and working parts, are far more susceptible to damage than the road wheels, so in a modern nation at war its industrial resources and communications form its Achilles’ heel. Mere common sense should tell us that if possible these are the points at which to strike. Pressure on “the spirit” is intimately connected with that on “the pocket,” a thorough and long-continued interruption of the normal life of a nation is as depressing and demoralizing as the intimidation of the people by methods of terrorism――which, even if temporarily successful, usually react among civilized nations to the detriment of the aggressor by stimulating the will to resist or by so outraging the moral sense of other nations as to pave the way for their intervention.