It is essential to note that the base is there for the sake of the ships. The ships are not there for the sake of the base. It is a fatal inversion of all sound principles of naval strategy to suppose that the ships owe, or can afford, to the base any other form of defence than that which is inherent in their paramount and primary task of controlling the maritime communications which lead to it. So long as they can do this the base will be exposed only to such attacks as can be delivered by a force which has evaded but not defeated the naval guard, and to this extent the base must be fortified and garrisoned; for, of course, if the naval guard has been decisively defeated, the control of maritime communications has passed into the hands of the enemy, and nothing but the advance of a relieving naval force, too strong for the enemy to resist, can prevent the base being invested from the sea and ultimately reduced. It will be seen from this how absurd it is ever to speak of a naval base as commanding the adjacent seas. As such it does not command, and never can command, any portion of the sea which lies beyond the range of its own guns. All that it ever does or can do is, by its resources for repair, refit, and supply, to enable the fleet based upon it constantly to renew its efficiency and mobility, and thereby to discharge its appointed task of controlling the maritime communications entrusted to its keeping. But such command is in all cases exercised by the fleet and not by the base. If the fleet is not there or not equal to its task, the mere possession of the base is nearly always a source of weakness and not of strength to the naval Power which holds it.