first, or gained during hostilities, by one belligerent of carrying
out considerable over-sea expeditions at will. In the Russian
war just mentioned the allies had such overwhelmingly superior
sea-power that the Russians abandoned to them without a struggle
the command of the sea; and the more recent landing in South
Africa, more than six thousand miles away, of a large British army
without even a threat of interruption on the voyage is another
instance of unchallenged command. In wars between great powers
and also between secondary powers, if nearly equally matched,
this absence of challenge is rare. The rule is that the command
of the sea has to be won after hostilities begin. To win it the
enemy's naval force must be neutralised. It must be driven into
his ports and there blockaded or 'masked,' and thus rendered
virtually innocuous; or it must be defeated and destroyed. The
latter is the preferable, because the more effective, plan. As
was perceptible in the Spanish-American war of 1898, as long
as one belligerent's fleet is intact or at large, the other is
reluctant to carry out any considerable expedition over-sea. In
fact, the command of the sea has not been secured whilst the
enemy continues to have a 'fleet in being.'[56]

[Footnote 55: _Influence_of_Sea-power_on_History_, 1890, p. 4.]

[Footnote 56: See _ante_, Sea-Power, p. 50.]

In 1782 a greatly superior Franco-Spanish fleet was covering
the siege of Gibraltar. Had this fleet succeeded in preventing
the revictualling of the fortress the garrison would have been
starved into surrender. A British fleet under Lord Howe, though
much weaker in numbers, had not been defeated and was still at