text: Chapter 5
  Note. Local security is a priority of work and the responsibility of all units as a force protection measure.
  Local security is the low-level security activities conducted near a unit to prevent surprise by the
  enemy (ADP 3-90). Local security involves avoiding detection or deceiving the enemy regarding
  friendly actions, positions, and intentions. Local security includes finding enemy forces in the
  immediate vicinity and knowing as much about their positions and intentions as possible. Units
  use active and passive measures to provide local security. Active patrolling and continuous
  reconnaissance are active measures that provide local security. Passive measures include using
  camouflage, movement control, noise and light discipline, proper communication procedures,
  ground sensors, night vision devices, and daylight sights.
  5-19. Security operations are extremely important when engaged in large-scale combat operations. The
  historic Arracourt vignette below demonstrates how incorporating security and applying security fundamentals
  in battle can lead to victory.
  Applying Security Fundamentals at Arracourt
  In September 1944, the 4th Armored Division constituted part of an operation intended to cross
  the Moselle River and isolate the city of Nancy. This operation concluded with elements of the
  4th Armored Division playing a significant role in disrupting German rear area elements and
  reinforcements to Nancy. The division then transitioned into an exploitation mission, heading
  further east into Lorraine and creating more havoc for German efforts to mount a coherent defense.
  The threat posed by the American armored division led the Germans to counterattack with
  elements drawn from the Fifth Panzer Army on 18 September. Part of their objective lay in
  destroying the scattered U.S. armored forces in and around the town of Arracourt. The German
  action triggered a series of fast moving and freewheeling engagements. These encounters
  placed the 4th Armored Division at a disadvantage. The Germans employed superior tanks,
  practiced infiltration tactics, and benefited from ground fog that protected them from allied
  aircraft. However, despite these advantages, the Germans suffered a significant defeat at
  Arracourt. They were generally out maneuvered and outfought by aggressive American, small
  unit tactics.
  American armored teams employed basic security measures to offset the initial surprise of the
  German attack. C Company, 37th Tank Battalion, for example, employed outposts to provide
  early warning of enemy activity. One of these outposts reported the noise of an enemy column
  shortly before midnight on the 18th. The outpost dispatched a patrol to investigate. When it
  identified tank tracks, a second patrol followed the tracks and pinpointed the German tanks in
  a bivouac position. The patrol directed artillery fire onto the enemy tanks and adjusted onto a
  nearby crossroads through which the tanks had to move as they retired.
  The following morning another C Company outpost reported contact with German forces. This
  outpost included a tank section and a smaller outpost further forward. The latter remained in
  contact with the tank section via a landline. The smaller outpost provided the tank section with
  early warning of approaching vehicles. Armed with this information, the American tank section
  quickly destroyed two of the German tanks as soon as they came into view.
  In this instance, C Company demonstrated the fundamentals of security. Outposts provided
  early and accurate warning of approaching enemy armor. The outposts provided reaction time
  and maneuver space that permitted the tank section to maneuver and destroy two enemy tanks.
  Positioned between the enemy and the main body of C Company, the outposts were oriented on
  the force to be secured. In each case, the outposts were able to perform continuous
  reconnaissance by reporting and tracking hostile movements. In the first example, the outpost
  maintained enemy contact using foot patrols that were able to track the enemy armor column
  and direct indirect fire upon it.