developments so far redress the balance of strength that we are able to
pass to the offensive. In the operations of armies the most usual means
employed are the holding of positions and forcing our superior enemy to
exhaust his strength in attacking them. Consequently the idea of military
defence is dominated by the conception of entrenched positions and
fortresses.

In naval warfare this is not so. At sea the main conception is avoiding
decisive action by strategical or tactical activity, so as to keep our
fleet in being till the situation develops in our favour. In the golden age
of our navy the keynote of naval defence was mobility, not rest. The idea
was to dispute the control by harassing operations, to exercise control at
any place or at any moment as we saw a chance, and to prevent the enemy
exercising control in spite of his superiority by continually occupying his
attention. The idea of mere resistance was hardly present at all.
Everything was counterattack, whether upon the enemy's force or his
maritime communications. On land, of course, such methods of defence are
also well known, but they belong much more to guerilla warfare than to
regular operations. In regular warfare with standing armies, however
brilliantly harassing operations and counter-attack are used, the
fundamental conception is the defended or defensible position.

Similarly at sea, although the essence of defence is mobility and an
untiring aggressive spirit rather than rest and resistance, yet there also
defended and defensible positions are not excluded. But they are only used
in the last resort. A fleet may retire temporarily into waters difficult of
access, where it can only be attacked at great risk, or into a fortified
base, where it is practically removed from the board and cannot be attacked
at all by a fleet alone. But the occasions on which such expedients can be
used at sea are far rarer than on land. Indeed except for the most
temporary purposes they can scarcely be regarded as admissible at sea,
however great their value on land. The reason is simple. A fleet
withdrawing to such a position leaves open to the enemy the ulterior
object, which is the control of sea communications, whereas on land an army
in a good position may even for a prolonged period cover the ulterior
object, which is usually territory. An army in position, moreover, is
always doing something to exhaust its opponent and redress the unfavourable
balance, but a