rman Conquest has established, that all attempts
to invade England have been made in the past and must be made in the
future across a sea not commanded by the intending invader. If he has
secured the command of the sea beforehand, there is nothing to prevent
the invasion except the consideration that he can attain his end--that
is, the subjugation of the nation's will--at less cost to himself. That
being premised, let us consider how the intending invader will set about
his task. There are three ways, and three ways only. First, he may seek
to overpower the British naval defence on the seas, that is to obtain
the command of the sea. If he can do that, the whole thing is done. Or
secondly, he may collect the military forces destined for the invasion
in ports suitable for the purpose, and when all is ready he may cover
their embarkation and transit by a naval force sufficient to overcome
any naval force which this country can direct against it. I have already
shown, however, that a force sufficient to do this with any certainty,
or even with any reasonable prospect of success, must needs be more than
sufficient to overpower the British naval defence and thereby to secure
the command of the sea, if the enemy were freed from the entangling and
wellnigh disabling necessity of providing for the safe conduct of an
unwieldy host of otherwise defenceless transports. In other words he is
putting the cart before the horse, a procedure which has never yet
succeeded in getting the cart to its destination. This second
alternative is then merely a clumsy and extremely inefficient way of
attaining the same end as the first, and need only be mentioned in order
to exclude it from further consideration.

There remains only a third alternative. This is to assemble the invading
military force at suitable ports as before, and to attempt to engage the
attention of the defending naval force by operations at a distance for a
time sufficient to secure the unmolested transit of the military
expedition. This is the method which has nearly always been employed by
an enemy projecting an invasion of this country. It has never yet
succeeded, because it always leads in the end to a situation which is
practically indistinguishable from that involved in the second
alternative, which I have already discussed and excluded. The naval and
the military elements in the enterprise of invasion being now, by the
hypothesis, separated in space and for that reason i