or a strait, depends, 1, upon situation (with reference
chiefly to communications), 2, upon its strength (inherent or
acquired), and, 3, upon its resources (natural or stored). As strength
and resources are matters which man can accumulate where suitable
situation offers, whereas he cannot change the location of a place in
itself otherwise advantageous, it is upon situation that attention
must primarily be fixed. Strength and resources may be artificially
supplied or increased, but it passes the power of man to move a port
which lies outside the limits of strategic effect. Gibraltar in
mid-ocean might have fourfold its present power, yet would be
valueless in a military sense.

The positions which are indicated on the map by the dark squares have
been selected, therefore, upon these considerations, after a careful
study of the inherent advantages of the various ports and coast-lines
of the Caribbean Sea and the Gulf. It is by no means meant that there
are not others which possess merits of various kinds; or that those
indicated, and to be named, exhaust the strategic possibilities of the
region under examination. But there are qualifying circumstances of
degree in particular cases; and a certain regard must be had to
political conditions, which may be said to a great extent to
neutralize some positions. Some, too, are excluded because
overshadowed by others so near and so strong as practically to embrace
them, when under the same political tenure. Moreover, it is a
commonplace of strategy that passive positions, fortified places,
however strong, although indispensable as supports to military
operations, should not be held in great number. To do so wastes force.
Similarly, in the study of a field of maritime operations, the number
of available positions, whose relative and combined influence upon the
whole is to be considered, should be narrowed, by a process of gradual
elimination, to those clearly essential and representative. To embrace
more confuses the attention, wastes mental force, and is a hindrance
to correct appreciation. The rejection of details, where permissible,
and understandingly done, facilitates comprehension, which is baffled
by a multiplication of minutiae, just as the impression of a work of
art, or of a story, is lost amid a multiplicity of figures or of
actors. The investigation precedent to formulation of ideas must be
close and minute, but that done, the unbiassed selection of the most
important