Acronym for US Army Special Operations Command. The monitor and command organization for all US Army Special Forces. It is part of US Special Operations Command (USSOCOM).

ARSOC was the first to obtain information on Liquid Ocelot's planned insurrection, passing it on to the Army. The CID dispatched investigative units over the course of several months to recon the situation, but contact was lost with five separate units during their mission. Rat Patrol Team 01, led by Meryl Silverburgh, is then dispatched to the Middle East where they discover Liquid.