FM 31-20

FM 31-20
Name	FM 31-20
Caption	Field Manual cover (illustrative)
Issued	United States Army
Subject	Small unit tactics, reconnaissance, patrolling
Country	United States

FM 31-20

FM 31-20 is a United States Army field manual that codifies small unit reconnaissance, patrolling, and security procedures for infantry and reconnaissance units. It synthesizes doctrine applicable to platoon- and company-level operations and integrates lessons from twentieth-century conflicts, training centers, and joint service experiments. The manual served as a reference for leaders, trainers, and staff officers tasked with preparing units for reconnaissance, surveillance, and direct-action missions.

Overview

FM 31-20 addresses reconnaissance and patrolling at the brigade, battalion, company, and platoon scale, laying out mission planning, movement techniques, observation and reporting, and contact drills. It emphasizes the role of reconnaissance in the combined arms context of operations alongside United States Army Infantry School, United States Army Forces Command, United States Marine Corps reconnaissance elements, and allied counterparts such as the British Army and Canadian Army. The manual reflects institutional input from Fort Benning, Fort Bragg, Fort Lewis, and training institutions like the National Training Center (United States) and the Joint Readiness Training Center.

Historical Development and Editions

FM 31-20 evolved from earlier U.S. doctrine developed during the interwar period and refined through experience in World War II, Korean War, and Vietnam War. Post-World War II publications from the United States Army Training and Doctrine Command and the Department of the Army incorporated reconnaissance lessons learned from the Battle of Okinawa, Battle of the Bulge, and Tet Offensive. Cold War pressures and NATO interoperability concerns influenced revisions that referenced practices from the North Atlantic Treaty Organization and exchanges with the British Army of the Rhine.

Subsequent editions responded to technological change driven by platforms and systems fielded by the United States Army Aviation Branch, HUMINT assets embedded with Special Forces (United States Army), and signals capabilities developed by the United States Army Signal Corps. Modern revisions aligned with operational concepts emerging from conflicts such as the Gulf War (1990–1991), the Iraq War, and the War in Afghanistan (2001–2021), integrating feedback from units assigned to III Corps (United States), XVIII Airborne Corps, and multinational coalitions like Coalition forces in Afghanistan.

Organization and Key Contents

The manual is organized into chapters covering mission analysis, reconnaissance planning, patrol organization, movement formations, observation and reporting, night operations, and actions on contact. It prescribes standard operating procedures for scouts, forward observers from the Field Artillery Branch, and liaison with Aviation Regiment assets and Military Intelligence Corps detachments. Annexes and appendices provide templates for reconnaissance reports, maps and overlays used with Defense Mapping Agency products, and checklists for equipment common to units at Fort Hood and similar posts.

Key contents include detailed descriptions of reconnaissance-in-force, zone reconnaissance, route reconnaissance, area reconnaissance, and security operations. It addresses employment of reconnaissance teams operating with armored elements like the M1 Abrams and mechanized units such as the Bradley Fighting Vehicle, as well as dismounted scouts and long-range surveillance teams that trained under the auspices of Long Range Surveillance (United States Army). The manual also maps command relationships linking company commanders, battalion S2/S3 sections, and corps-level intelligence centers like Intelligence and Security Command.

Tactical Doctrines and Techniques

FM 31-20 codifies movement techniques—file, column, staggered column, wedge, and squad-level formations—alongside observation post selection and camouflage influenced by experiences from Operation Desert Storm and jungle operations in Southeast Asia. It details contact drills such as break contact, assault, and hasty attack, integrating indirect fire coordination with the Field Artillery Branch and close air support procedures coordinated through the Air Force Tactical Air Control Party and Marine Tactical Air Command Squadron frameworks.

The manual emphasizes reporting standards like SALUTE and 5W/3D formats used by reconnaissance soldiers communicating with Forward Air Controllers, Joint Terminal Attack Controllers, and brigade intelligence cells. It covers night operations employing night vision devices fielded by the Night Vision and Electronic Sensors Directorate and countermobility techniques including obstacle emplacement influenced by doctrine from the Engineer Regiment and obstacle clearing taught at Fort Leonard Wood.

Influence and Legacy

FM 31-20 influenced subsequent doctrine within the United States Army Combat Arms community and contributed to training syllabi at the United States Army War College, Command and General Staff College, and service academies such as the United States Military Academy. Its principles informed allied doctrine adopted by partners within NATO and were cited in after-action reviews conducted by units returning from Operation Iraqi Freedom and Operation Enduring Freedom.

Elements of FM 31-20 persist in modern publications from Doctrine 2015-era revision cycles under the U.S. Army Training and Doctrine Command and continue to shape reconnaissance tradecraft taught at centers like the National Training Center (United States) and Joint Readiness Training Center. The manual’s focus on disciplined observation, disciplined movement, and disciplined reporting remains a foundation for reconnaissance professionals in organizations ranging from Special Forces (United States Army), 75th Ranger Regiment, and conventional reconnaissance units to multinational partners operating in expeditionary and stability operations.

Category:United States Army field manuals