4-40. A screen primarily provides early warning. It observes, identifies, and reports enemy actions. A screen provides the least amount of protection of any security mission. Generally, a screening force engages
and destroys enemy reconnaissance elements within its capabilities, but otherwise fights only in self-defense.
PURPOSES
4-41. A screen is appropriate to cover gaps between forces, the exposed flanks or rear of stationary and moving forces, or the front of a stationary formation. It is used when the likelihood of enemy contact is remote, the expected enemy force is small, or the friendly main body needs only a minimum amount of time once it is warned to react effectively. Screening is largely accomplished by establishing a series of OPs and conducting patrols to ensure adequate surveillance of the assigned sector. Purposes of the operation include the following:
•
Prevent enemy ground elements from passing through the screen undetected or unreported.•
Maintain continuous surveillance of all avenues of approach into the sector under all visibility conditions.•
Destroy or repel enemy reconnaissance elements within capability.•
Locate the lead elements of each enemy advance guard force and determine their direction of movement.•
Maintain contact with enemy forces and report any activity in sector.•
Impede and harass the enemy within capability while displacing.•
Maintain contact with the enemy main body and any enemy security forces operating on the flanks of friendly forces.STATIONARY SCREEN
4-42. The company team commander first takes a close look at infiltration routes into the screen sector, then assigns surveillance responsibility to the team’s subordinate elements. He designates locations of OPs, which should be in depth through the sector. The OPs are normally manned by sections within the company team. The commander identifies the enemy’s likely axes of attack or infiltration routes; if necessary, he identifies additional control measures (such as NAIs, PLs, TRPs, or checkpoints) to assist in movement control and in tracking of enemy elements. The company team conducts mounted and dismounted patrols to reconnoiter areas that cannot be observed from OPs.
4-43. Once the enemy is detected from an OP, the screening force normally engages him with indirect fires. This prevents the enemy from penetrating the screen line and does not compromise the location of the OP. Within its capability, the screening force may destroy enemy reconnaissance assets with direct fires if indirect fires cannot accomplish the task. (For additional details, see paragraphs 4-51 and 4-53 on the discussion of actions against enemy reconnaissance elements in the guard segment). The screening force also impedes and harasses other enemy elements, primarily through the use of indirect fires. If enemy pressure threatens the security of the screening force, the unit normally reports
MOVING SCREEN
4-44. The company team can conduct a moving screen to the flanks or rear of the screened force. The movement of the screen is keyed to time and distance factors associated with the movement of the friendly main body.
Moving Flank Screen
4-45. Responsibilities for a moving flank screen begin at the front of the main body’s lead combat element and end at the rear of the protected force. In conducting a moving flank screen, the company team either occupies a series of temporary OPs along a designated screen line or, if the protected force is moving too fast, continues to move while maintaining surveillance and preparing to occupy a designated screen line. The four basic methods of controlling movement along the screened flank are described below. The screening force may use one or more of these methods as the speed of movement of the protected force changes or contact is made.
Alternate Bounds by Individual Observation Post
4-46. This method is used when the protected force is advancing slowly or enemy contact is likely along the screen line. Designated elements of the screening force move to and occupy new OPs as dictated by the enemy situation and the movement of the main body. Other elements remain stationary, providing overwatch and surveillance, until the moving elements establish their new positions; these elements then move to new positions while the now-stationary elements provide overwatch and surveillance. This sequence continues as needed. The method of alternate bounding by individual OP is secure but slow.
Alternate Bounds by Unit
4-47. This method is used when the protected force is advancing slowly or enemy contact is likely along the screen line. Designated elements of the screening force move and occupy new positions as dictated by the enemy situation and the movement of the main body. Other elements remain stationary, providing overwatch, and surveillance, until the moving elements establish their new positions; these elements then move to new positions while the now-stationary elements provide overwatch and surveillance. This sequence continues as needed. The method of alternate bounding by unit is secure but slow.
4-48. Successive bounds. The screening element uses this method when enemy contact is possible and the main body makes frequent short halts during movement. Each platoon of the screening force occupies a designated portion of the screen line each time the main body stops.
When main body movement resumes, the platoons move simultaneously, retaining their relative position as they move forward.
4-49. Continuous marching. This method is used when the main body is advancing rapidly at a constant rate and enemy contact is not likely. The screening force maintains the same rate of movement as the main body, at the same time conducting surveillance as necessary.
Stationary screen lines are planned along the movement route, but the screening force occupies them only as necessary to respond to enemy action.
4-50. Moving rear screen. A moving rear screen may be established to the rear of a main body force conducting an offensive operation or between the enemy and the rear of a force conducting a retrograde operation. In either case, movement of the screen is keyed to the movement of the main body or to the requirements of the enemy situation; the operation is normally controlled by movement to a series of PLs.