fourth point of contact

fourth point of contact
 n.— «You can bitch and whine all you want that armor “shouldn’t be used in cities,” but you know what?…if they put my “fourth point of contact” in a city, you can bet I am personally going to be screaming for armored support.» —“An infantryman’s thoughts on armor” by Robert Bateman Armor Jan. 1, 2001. (source: Double-Tongued Dictionary)