Factors of dispersion and concentration are also involved in apportionment of fighting strength.
While undue dispersion may result in lack of adequate fighting strength where required, a certain degree of dispersion may be necessary to meet the demands of movement and of freedom of action. Serious errors in this regard, however, may result in inability to furnish support where needed, and in consequent punishment or isolation of one or more valuable detachments.
In distant operations some dispersion is required to safeguard long lines of communication. The requirements for this purpose may sometimes be so great that, unless the total available strength is adequate, a due apportionment to the guarding of long lines of communication may so weaken the main force as to prevent the attainment of the objective. (See also [page 63].)
Proper dispersion is, therefore, a requirement to be met, while undue dispersion is to be avoided. But realization is also necessary, in this connection, that there is an equal danger in over-concentration. An undue concentration of means at any point may subject such a force to unnecessary loss. Another disadvantage may be lack of adequate fighting strength elsewhere.
Accordingly, axiomatic advice that it is unwise to divide a total force, while containing a sound element of caution, is misleading and inadequate, for division is often necessary or desirable. To be adequate, a maxim or rule relating to division of force should indicate when, and in what measure, such division may or may not be necessary or desirable. (See also [page 25].)
Similarly inadequate, however true as a generality, is the statement that the requirements of effective warfare are met by bringing superiority to bear at the decisive time and place. Such an injunction is of little assistance in solving practical problems as to the appropriate degree of superiority, and as to the proper time and place.
In like manner, any rule is faulty which advises a commander to seek the solution of his problems by always bringing to bear his elements of strength against the hostile elements of weakness. It may be found, on occasion, that it is necessary or desirable to act with strength against strength.
But it is equally faulty to maintain that action, to be effective, seeks always to deal with the enemy by first destroying his elements of strength. Even when the strongest opposition cannot be defeated by direct action of this nature, success may still be possible by first disposing of elements of weakness. When the stronger elements of a hostile combination cannot be defeated without undue loss, yet cannot stand without the weaker, consideration may well be given to an apportionment of fighting strength on the basis of seeking a decision against the latter. The defeat of a relatively small force at a distance from the area where the main forces are concentrated in opposition, may hasten the attainment of the ultimate objective.
The main effort, where the greater force is employed, may be identical with the effort contributing most directly to the final result. This identity, however, does not always exist, and the decisive influence is frequently exerted by a relatively small force, sometimes at a distance from the principal area of action.
Diversions (see also as to feints, [page 59]) are not likely to be profitable unless constituting a sufficient threat, or unless offering apparent advantages to the enemy which he feels that he cannot forego. Success will attend justified diversions if they lead the enemy to reapportion his fighting strength to meet the threat, either because he expects repetitions (see [page 73], as to raids), or because the area involved may become a new theater of action, or for other pertinent reasons.