FM 2-0 is the Army's keystone manual for military intelligence (MI) doctrine. It describes: 1. The fundamentals of intelligence operations. 2. The operational environment (OE). 3. Intelligence in unified action. 4. The Intelligence Battlefield Operating System (BOS). 5. Intelligence considerations in strategic readiness. 6. The intelligence process. 7. MI roles and functions within the context of Army operations. This manual provides doctrinal guidance for the Intelligence BOS actions in support of commanders and staffs. It also serves as a reference for personnel who are developing doctrine; tactics, techniques, and procedures (TTP); materiel and force structure; and institutional and unit training for intelligence operations. This manual provides MI guidance for all commanders, staffs, trainers, and MI personnel at all echelons. It forms the foundation for MI and the Intelligence BOS doctrine development, and applies equally to the Active Component (AC), United States Army Reserve (USAR), and Army National Guard (ARNG). It is also intended for commanders and staffs of joint and combined commands, US Naval and Marine Forces, units of the US Air Force, and the military forces of multinational partners.