More than 7,000 active duty troops have been told to deploy to Texas, Arizona and California. They are a mix of forces, including military police, an assault helicopter battalion, various communications, medical and headquarters units, combat engineers, planners and public affairs units.
As of Friday, one week after the Pentagon acknowledged that Defense Secretary Jim Mattis had approved a Department of Homeland Security request for military support at the border, the troop deployment was still unfolding, with about 3,500 at staging bases in the Southwest. Of those, about 2,250 active duty troops are at staging bases in Texas, about 1,100 Marines are at Camp Pendleton in California and fewer than 200 are in Arizona. About 100 troops are actually on the border, at the port crossing near McAllen, Texas.
Most of the troops are being used to facilitate the movement of border patrol agents, house them, feed them and provide some of their protection.