If the object of naval warfare is to control communications, then the
fundamental requirement is the means of exercising that control. Logically,
therefore, if the enemy holds back from battle decision, we must relegate
the battle-fleet to a secondary position, for cruisers are the means of
exercising control; the battle-fleet is but the means of preventing their
being interfered with in their work. Put it to the test of actual practice.
In no case can we exercise control by battleships alone. Their
specialisation has rendered them unfit for the work, and has made them too
costly ever to be numerous enough. Even, therefore, if our enemy had no
battle-fleet we could not make control effective with battleships alone. We
should still require cruisers specialised for the work and in sufficient
numbers to cover the necessary ground. But the converse is not true. We
could exercise control with cruisers alone if the enemy had no battle-fleet
to interfere with them.

If, then, we seek a formula that will express the practical results of our
theory, it would take some such shape as this. On cruisers depends our
exercise of control; on the battle-fleet depends the security of control.
That is the logical sequence of ideas, and it shows us that the current
maxim is really the conclusion of a logical argument in which the initial
steps must not be ignored. The maxim that the command of the sea depends on
the battle-fleet is then perfectly sound so long as it is taken to include
all the other facts on which it hangs. The true function of the
battle-fleet is to protect cruisers and flotilla at their special work. The
best means of doing this is of course to destroy the enemy's power of
interference. The doctrine of destroying the enemy's armed forces as the
paramount object here reasserts itself, and reasserts itself so strongly as
to permit for most practical purposes the rough generalisation that the
command depends upon the battle-fleet.