ished, or at best it is
only partially, and it may be only temporarily, established by driving
the main fleets of the enemy into ports which are inaccessible to naval
force alone. They must not only be driven there but compelled to remain
there. This has generally been done in the past, and according to many,
but not all, naval authorities, it will generally have to be done in the
future by the operation known as blockade, whereby the enemy is
prevented from coming out, or is compelled if he does come out to fight
a superior force lying in wait outside. As a matter of fact, inasmuch as
a blockade to be really deterrent must be conducted by a blockading
force superior to that which is blockaded--for otherwise the latter need
not shun an engagement in the open with the former--it can rarely be the
interest of the blockader to prevent the exit of his adversary, since by
the hypothesis if he could get him out he could beat him. But the
blockade must nevertheless be maintained, because, although the
blockaded fleet cannot by that means be destroyed, it can, at any rate,
be immobilized and wiped off the board so long as it remains where it
is.

The situation in which a blockade is set up by one belligerent and
submitted to by the other is not identical with an effective command of
the sea, though in certain circumstances it may approximate very closely
to it. The blockaded forces may not be so thoroughly intimidated by the
superior forces of the blockaders that they could not or would not, if
they could, seek a favourable opportunity for breaking or evading the
blockade imposed upon them. They may merely be waiting in a position
unassailable by naval force alone until the blockading forces are so
weakened through incessant torpedo attack, through the wear and tear
inflicted on them by the nature of the service on which they are
engaged, through stress of weather, through the periodical necessity
which compels even the best found ships to withdraw temporarily from the
blockade for the purposes of repair, refit, and replenishment of their
stores, and through the fatigue imposed on their officers and crews by
the incessant vigilance which a blockade requires as to afford them a
favourable opportunity of challenging a decision in the open. Or, again,
if the forces of the blockaded belligerent are distributed between two
or more of his fortified ports, he may attempt an evasion of the
blockade at two or more of them for the purpos