f suitable strength. It is to be observed that each element
possessed the characteristic of mobility. We have to deal here
more especially with the naval element, and we must study the
manner in which it operates.

Naval war is sea-power in action; and sea-power, taken in the
narrow sense, has limitations. It may not, even when so taken,
cease to act at the enemy's coast-line, but its direct influence
extends only to the inner side of a narrow zone conforming to that
line. In a maritime contest each side tries to control the ocean
communications and to prevent the other from controlling them. If
either gains the control, something in addition to sea-power
strictly defined may begin to operate: the other side's territory
may be invaded or harassed by considerable raids, and its commerce
may be driven from the sea. It will be noticed that control of
ocean communications is the needful preliminary to these. It
is merely a variant of the often employed expression of the
necessity, in war, of obtaining command of the sea. In the case
of the most important portion of the British Empire, viz. the
United Kingdom, our loss of control of the ocean communications
would have a result which scarcely any foreign country would
experience. Other countries are dependent on importations for
some part of the food of their population and of the raw material
of their industry; but much of the importation is, and perhaps
all of it may be, effected by land. Here, we depend upon imports
from abroad for a very large part of the food of our people,
and of the raw material essential to the manufacture of the
commodities by the exchange of which we obtain necessary supplies;
and the whole of these imports come, and must come to us, by
sea. Also, if we had not freedom of exportation, our wealth and
the means of supporting a war would disappear. Probably all the
greater colonies and India could feed their inhabitants for a
moderately long time without sea-borne imports, but unless the
sea were open to them their prosperity would decline.

This teaches us the necessity to the British Empire of controlling
our maritime communications, and equally teaches those who may
one day be our enemies the advisability of preventing us from
doing so. The lesson in either case is driven farther home by
other considerations connected with communications. In war a
belligerent has two tasks before him. He has to defend himself
and hurt his enemy. The more he hurt