It may also be objected that the blockading of even a defenseless
coast would cost the blockading country a good deal of money, by
reason of the loss of trade with that country. True; but war is
always expensive, and the blockade would be very much more expensive
to the blockaded country; and though it might hold out a long while,
it would be compelled to yield in the end, not only because of the
blockade itself but because of the pressure of neutral countries;
and the longer it held out, the greater the indemnity it would
have to pay. The expense of blockading would therefore be merely
a profitable investment.

The author is aware that actual invasion of a country from the
sea would be a greater disaster than blockade, and that defense
against invasion has often been urged in Great Britain as a reason
for a great navy; so that the primary reason for a navy might be
said to be defense against invasion. But why should an enemy take
the trouble to invade us? Blockade is easier and cheaper, and can
accomplish almost everything that an enemy desires, especially
if it be enlivened by the occasional dropping of thousand-pound
shells into Wall Street and the navy-yard.

While, however, the _primary_ use of naval power seems to be to
prevent blockade, a navy, like any other weapon, may be put to
any other uses which circumstances indicate. For instance, the
Northerners in the Civil War used the navy not to prevent blockade,
but to make blockade; the Japanese used the navy to cover the
transportation of their armies to Manchuria and Corea; and Great
Britain has always used her navy to protect her trade routes.

A general statement of the various uses of a navy has been put into