The problem of such co-ordination is one that is susceptible of widely varying solutions.  It may be that the command of the sea is of so urgent an importance that the army will have to devote itself to assisting the fleet in its special task before it can act directly against the enemy’s territory and land forces; on the other hand, it may be that the immediate duty of the fleet will be to forward military action ashore before it is free to devote itself whole-heartedly to the destruction of the enemy’s fleets.  The crude maxims as to primary objects which seem to have served well enough in continental warfare have never worked so clearly where the sea enters seriously into a war.  In such cases it will not suffice to say the primary object of the army is to destroy the enemy’s army, or that of the fleet to destroy the enemy’s fleet.  The delicate interactions of the land and sea factors produce conditions too intricate for such blunt solutions.  Even the initial equations they present are too complex to be reduced by the simple application of rough-and-ready maxims.  Their right handling depends upon the broadest and most fundamental principles of war, and it is as a standpoint from which to get a clear and unobstructed view of the factors in their true relations that a theory of war has perhaps its highest value.

The theory which now holds the field is that war in a fundamental sense is a continuation of policy by other means.  The process by which the continental strategists arrived at it involved some hard philosophical reasoning.  Practical and experienced veterans as they were, their method is not one that works easily with our own habit of thought.  It will be well, therefore, to endeavour first to present their conclusions in a concrete form, which will make the pith of the matter intelligible at once.  Take, now, the ordinary case of a naval or military Staff being asked to prepare a war plan against a certain State and to advise what means it will require.  To any one who has considered such matters it is obvious the reply must be another question—­What will the war be about?  Without a definite answer or alternative answers to that question a Staff can scarcely do more than engage in making such forces as the country can afford as efficient as possible.  Before they take any sure step further they must know many things.  They must know whether they are expected to take something from the enemy, or to prevent his taking something either from us or from some other State.  If from some other State, the measures to be taken will depend on its geographical situation and on its relative strength by land and sea.  Even when the object is clear it will be necessary to know how much value the enemy attaches to it.  Is it one for which he will be likely to fight to the death, or one which he will abandon in the face of comparatively slight resistance?  If the former, we cannot hope to succeed without entirely overthrowing his powers of resistance.  If the latter, it will suffice, as it often has sufficed, to aim at something less costly and hazardous and better within our means.  All these are questions which lie in the lap of Ministers charged with the foreign policy of the country, and before the Staff can proceed with a war plan they must be answered by Ministers.