A base of fire is a military term for a supporting force that provides overwatch and covering fire to other advancing units while they are executing fire and movement tactics. A base of fire can be a platoon during company fire and movement, by individual armoured fighting vehicles (esp. tanks) or infantry sections, in platoon fire and movement, or even by fireteams or individual soldiers, in the final stages of an assault. -- Wikipedia.
Suppress the Enemy.
a. The platoon leader determines if the squad in contact can gain suppressive fire against the enemy based on the volume and accuracy of the enemy's return fire.
(1) If the answer is YES, he directs the squad (with one or both machine guns) to continue suppressing the enemy:
(a) The squad in contact destroys or suppresses enemy weapons that are firing most effectively against it; normally crew-served weapons.
(b) The squad in contact places screening smoke (M203) to prevent the enemy from seeing the maneuver element.
(2) If the answer is NO, the platoon leader deploys another squad and the second machine gun team to suppress the enemy position. (The platoon leader may direct the platoon sergeant to position this squad and one or both machine gun teams in a better support-by-fire position.) -- FM 7-8 INFANTRY RIFLE PLATOON AND SQUAD, Chapter 4, Battle Drills.
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