successful actions.

2. _Local and temporary control_ may be secured by:--

(a) A defensive action not necessarily entirely successful
(containing).

(b) Forcing concentration on the enemy elsewhere (diversion).

(c) Superior concentration so as to render impotent the enemy's force
available in the special theatre of operations (masking or containing).

BLOCKADE

Blockades are of two natures, according to the object review. The object
may be:--

(d) Blockade.

i. _Close blockade_ to prevent the enemy putting to sea. The object
being usually to secure local or temporary control.

ii. _Observation blockade_, to force the enemy to put to sea _by
occupying the common lines of communications_ (_see_ below). In this
case you are seeking a decision as a step towards general control.

Both natures are operations upon the lines of passage and communication,
but in case (1) the primary intention is defensive, to secure our own line;
in case (2) the primary intention is offensive, to seize the enemy's line
and compel him to expose himself in an attempt to recover it.

GENERAL RULES FOR CONDUCTING BLOCKADES

In case (1) (defensive intention) blockade should be as close as is
compatible with security from torpedo attack.

In case (2) (offensive intention) it should be as distant as is compatible
with bringing enemy to action if he comes out.

Examples:--_Case_ (1): First stage of Togo's blockade of Port Arthur.
_Case_ (2): Nelson off Toulon.
_Confusion of the two_: Sampson's attempt to close Santiago
simultaneously with an attempt to force Cervera to sea.

THE PECULIARITY OF MARITIME COMMUNICATIONS

Since the whole idea of command of the sea and the whole theory of blockade
rest on the control of communications, neither can be fully apprehended
without a thorough understanding of the nature of maritime communications.

Ashore, the respective lines of communications of each belligerent tend to
run more or less approximately in opposite directions, until they meet in
the theatre of operations or the objective point.

At sea the reverse is the case; for in maritime warfare the great lines of
communications of either belligerent tend to run approximately parallel,
if, indeed, they are not identical.

Thus, in the case of a war with Germany, the object of which lay in the
Eastern Mediterranean, or in America, or South Africa, our respective lines
of communica