Defense

Positions and Intrenchments

503. Requirements of a good defensive position. The first requirement of a good position is a clear field of fire and view to the front and exposed flanks to a distance of 600 to 800 yards or more. The length of front should be suitable to the size of the command and the flanks should be secure. The position should have lateral communication and cover for supports and reserves. It should be one which the enemy can not avoid, but must attack or give up his mission.

A position having all these advantages will rarely, if ever, be found. The one should be taken which conforms closest to the description. (489)

504. Utilization of natural cover; construction of fieldworks and obstacles. The natural cover of the position should be fully utilized. In addition, it should be strengthened by fieldworks and obstacles.

The best protection is afforded by deep, narrow, inconspicuous trenches. If little time is available, as much as practicable must be done. That the fieldworks may not be needed should not cause their construction to be omitted, and the fact that they have been constructed should not influence the action of a commander, if conditions are found to be other than expected. (490)

505. Construction of communicating and cover trenches, head cover, etc. When time and troops are available the preparations include the necessary communicating and cover trenches, head cover, bombproofs, etc. The fire trenches should be well supplied with ammunition.

The supports are placed close at hand in cover trenches when natural cover is not available. (491)

506. Dummy trenches. Dummy trenches frequently cause the hostile artillery to waste time and ammunition and to divert its fire. (492)

507. Location, extent, garrison, etc., of fieldworks. The location, extent, profile, garrison, etc., of fieldworks are matters to be decided by the infantry commanders. Officers must be able to choose ground and properly intrench it. (See "Field Fortifications," Chapter XVI, Part III.) (493)

508. Outlining trace of trenches in combat exercises. In combat exercises, when it is impracticable to construct the trenches appropriate to the exercise, their trace may be outlined by bayonets, sticks, or other markers, and the responsible officers required to indicate the profile selected, method and time of construction, garrisons, etc. (494)

Deployment for Defense

509. Density of whole deployment. The density of the whole deployment depends upon the expected severity of the action, the character of the enemy, the condition of the flanks, the field of fire, the terrain, and the available artificial or natural protection for the troops. (495)

510. Density of firing line. If exposed, the firing line should be as dense in defense as in attack. If the firing line is well intrenched and has a good field of fire, it may be made thinner.

Weaker supports are permissible. For the same number of troops the front occupied on the defensive may therefore be longer than on the offensive, the battalions placing more companies in the firing line. (496)

511. Strength in rear to be increased when change from defensive to offensive is contemplated. If it is intended only to delay the enemy, a fairly strong deployment is sufficient, but if decisive results are desired, a change to the offensive must be contemplated and the corresponding strength in rear provided. This strength is in the reserve, which should be as large as the demands of the firing line and supports permit. Even in a passive defense the reserve should be as strong as in the attack; unless the flanks are protected by other means. (497)

512. Post of supports; cover for supports. Supports are posted as close to the firing line as practicable and reinforce the latter according to the principles explained in the attack. When natural cover is not sufficient for the purpose, communicating and cover trenches are constructed. If time does not permit their construction, it is better to begin the action with a very dense firing line and no immediate supports than to have supports greatly exposed in rear. (498)

513. Post of reserve. The reserve should be posted so as to be entirely free to act as a whole, according to the developments. The distance from firing line to reserve is generally greater than in the attack. By reason of such a location the reserve is best able to meet a hostile enveloping attack; it has a better position from which to make a counter attack; it is in a better position to cover a withdrawal and permit an orderly retreat.

The distance from firing line to reserve increases with the size of the reserve. (499)

514. Post of reserve when situation is no longer in doubt. When the situation is no longer in doubt, the reserve should be held in rear of the flank which is most in danger or offers the best opportunity for counter attack. Usually the same flank best suits both purposes. (500)

515. Detaching part of reserve to protect opposite flank. In exceptional cases, on broad fronts, it may be necessary to detach a part of the reserve to protect the opposite flank. This detachment should be the smallest consistent with its purely protective mission. (501)

516. Assignment of front to units. The commander assigns to subordinates the front to be occupied by them. These, in turn, subdivide the front among their next lower units in the firing line. (502)

517. Division of extended position into sections. An extended position is so divided into sections that each has, if practicable, a field of fire naturally made distinct by the terrain.

Unfavorable and unimportant ground will ordinarily cause gaps to exist in the line. (503)

518. Size of units occupying sections; battalions to be kept intact. The size of the unit occupying each section depends upon the latter's natural strength, front, and importance. If practicable, battalions should be kept intact and assigned as units to sections or parts of sections. (504)

519. Adjoining sections or machine guns to cover dead space. Where important dead space lies in front of one section, an adjoining section should be instructed to cover it with fire when necessary, or machine guns should be concealed for the like purpose. (505)

520. Advanced posts and other dispersion to be avoided. Advanced posts, or any other form of unnecessary dispersion, should be avoided. (506)

521. Position itself not fully occupied until infantry attack begins. Unless the difficulty of moving the troops into the position be great, most of the troops of the firing line are held in rear of it until the infantry attack begins. The position itself is occupied by a small garrison only, with the necessary outguards or patrols in front. (507)

522. Fire alone unable to stop attack. Fire alone can not be depended upon to stop the attack. The troops must be determined to resort to the bayonet, if necessary. (508)

523. Steps to be taken if night attack is expected. If a night attack or close approach by the enemy is expected, troops in a prepared position should strengthen the outguards and firing line and construct as numerous and effective obstacles as possible. Supports and local reserves should move close to the firing line and should, with the firing line, keep bayonets fixed. If practicable, the front should be illuminated, preferably from the flanks of the section. (509)

524. Short range fire and bayonet in night attack. Only short range fire is of any value in resisting night attacks. The bayonet is the chief reliance. (See Night Operations pars. 580–590.) (510)

Counter Attack

525. Passive defense; only offensive wins. The passive defense should be assumed only when circumstances force it. Only the offensive wins. (511)

526. Active defense seeks favorable decision; counter attack necessary. An active defense seeks a favorable decision. A favorable decision can not be expected without counter attack. (512)

527. Protection of flanks by natural obstacles necessary in passive defense position. A passive defense in a position whose flanks are not protected by natural obstacles is generally out of the question. (513)

528. Post of troops for counter attack. Where the defense is assumed with a view to making a counter attack, the troops for the counter attack should be held in reserve until the time arrives for such attack. The defensive line should be held by as few troops as possible in order that the force for the offensive may be as large as possible.

The force for the counter attack should be held echeloned in rear of the flank which offers it the greatest advantage for the proposed attack. (514)

529. Manner of making counter attack. The counter attack should be made vigorously and at the proper time. It will usually be made:

By launching the reserve against the enemy's flank when his attack is in full progress. This is the most effective form of counter attack.

Straight to the front by the firing line and supports after repulsing the enemy's attack and demoralizing him with pursuing fire.

Or, by the troops in rear of the firing line when the enemy has reached the defensive position and is in disorder. (515)

530. Minor counter attacks. Minor counter attacks are sometimes necessary in order to drive the enemy from important positions gained by him. (516)

Delaying Action

531. The important considerations in a delaying action. When a position is taken merely to delay the enemy and to withdraw before becoming closely engaged, the important considerations are:

The enemy should be forced to deploy early. The field of fire should therefore be good at distances from 500 to 1,200 yards or more; a good field of fire at close range is not necessary.

The ground in rear of the position should favor the withdrawal of the firing line by screening the troops from the enemy's view and fire as soon as the position is vacated. (517)

532. Thin firing line answers purpose; purposes of supports and reserve. A thin firing line using much ammunition will generally answer the purpose. Supports are needed chiefly to protect the flanks.

The reserve should be posted well in rear to assist in the withdrawal of the firing line. (518)

533. Value of artillery. Artillery is especially valuable to a delaying force. (519)

Meeting Engagements

534. Characteristics of meeting engagements. Meeting engagements are characterized by the necessity for hasty reconnaissance, or the almost total absence of reconnaissance; by the necessity for rapid deployment, frequently under fire; and usually by the absence of trenches or other artificial cover. These conditions give further advantages to the offensive. (520)

535. General action on meeting enemy. The whole situation will usually indicate beforehand the proper general action to be taken on meeting the enemy. (521)

536. Meagerness of information; qualities of commander to be relied upon. Little fresh information can be expected. The boldness, initiative, and determination of the commander must be relied upon. (522)

537. Meeting engagement affords ideal opportunity to certain commanders. A meeting engagement affords an ideal opportunity to the commander who has intuition and quick decision and who is willing to take long chances. His opponent is likely to be overcautious. (523)

538. The mission determines method of attack. The amount of information that the commander is warranted in awaiting before taking final action depends entirely upon his mission. One situation may demand a blind attack; another may demand rapid, partial deployment for attack, but careful and time-consuming reconnaissance before the attack is launched. (524)

539. Advantage accrues to side deploying the faster. A great advantage accrues to the side which can deploy the faster. The advantage of a close-order formation, favoring rapid deployment, becomes more pronounced with the size of the force. (525)

540. Advantages of first troops to deploy. The first troops to deploy will be able to attack with longer firing lines and weaker supports than are required in the ordinary case. But if the enemy succeeds in deploying a strong defensive line, the attack must be strengthened accordingly before it is wasted. (526)

541. Things to be done by the leading troops. If the situation warrants the advance, the leading troops seek to deploy faster than the enemy, to reach his flanks, check his deployment, and get information. In any event, they seek to cover the deployment of their own troops in rear—especially the artillery—and to seize important ground. (527)

542. Post of commander of long column meeting enemy; function of advance guard; action of column. The commander of a long column which meets the enemy should be with the advance guard to receive information promptly and to reconnoiter. If he decides to fight, the advance guard must hold the enemy while the commander formulates a plan of action, issues the necessary orders, and deploys the main body. Meantime, the column should be closing up, either in mass or to form line of columns, so that the deployment, when determined upon, may be made more promptly. (528)

543. Action of advance guard prior to receipt of orders. The action of the advance guard, prior to the receipt of orders, depends upon the situation. Whether to attack determinedly or only as a feint, or to assume the defensive, depends upon the strength of the advance guard, the terrain, the character of the hostile force encountered, and the mission and intentions of the commander of the whole. (529)

544. Main body should be used as a whole and not put into action piecemeal. If the enemy is beforehand or more aggressive, or if the advance guard is too weak, it may be necessary to put elements of the main body into action as fast as they arrive, in order to check him. This method should be avoided; it prevents the formation and execution of a definite plan and compels piecemeal action. The best results are obtained when the main body is used as a whole. (530)

Withdrawal from Action

545. Withdrawal generally effected at heavy cost; rear guard and distance to be placed between enemy and defeated troops. The withdrawal of a defeated force can generally be effected only at a heavy cost. When it is no longer possible to give the action a favorable turn and the necessity for withdrawal arises, every effort must be made to place distance and a rear guard between the enemy and the defeated troops. (531)

546. Use of artillery, machine guns, and cavalry. Artillery gives especially valuable assistance in the withdrawal. The long-range fire of machine guns should also be employed. Cavalry assists the withdrawal by charging the pursuing troops or by taking flank positions and using fire action. (532)

547. Use of reserve to check the pursuit. If an intact reserve remains, it should be placed in a covering position, preferably on a flank, to check the pursuit and thus enable the defeated troops to withdraw beyond reach of hostile fire.

The covering position of the reserve should be at some distance from the main action, but close enough to bring the withdrawing troops quickly under the protection of its fire. It should have a good field of fire at effective and long ranges and should facilitate its own safe and timely withdrawal. (533)

548. Part of line to be withdrawn first; retreating troops to be gotten under control as soon as possible. If the general line is divided, by terrain or by organization, into two or more parts, the firing line of the part in the least danger from pursuit should be withdrawn first. A continuous firing line, whose parts are dependent upon one another for fire support, should be withdrawn as a whole, retiring by echelon at the beginning of the withdrawal. Every effort must be made to restore the organizations, regain control, and form column of march as soon as the troops are beyond the reach of hostile fire.

As fast as possible without delaying the march, companies, and the larger units should be reformed, so that the command will again be well in hand. (534)

549. Action taken by commander; selection of rendezvous point. The commander of the whole, having given orders for withdrawal, should go to the rear, select a rendezvous point, and devote himself to the reorganization of his command.

The rendezvous point is selected with regard to the natural channels of movement approximately straight to the rear. It should be distant from the battlefield and should facilitate the gathering and protection of the command. (535)