FM 3-21.8 is the principal manual for United States Army doctrine concerning light infantry tactics. It also addresses rifle platoon and squad non-combat operations across the spectrum of conflict. Content discussions include principles, tactics, techniques, procedures, terms, and symbols that apply to small unit operations in the current operational environment (COE).

The primary audiences for this manual are Infantry rifle platoon leaders, platoon sergeants, and squad and fire team leaders. Secondary audiences include, instructors in U.S. Army Training and Doctrine Command (TRADOC) schools, writers of Infantry training literature, other Infantry leaders and staff officers, and Reserve Officer Training Candidate (ROTC) and military academy instructors. Anyone attempting to gain an understanding of military concepts and operations will benefit from reading this book.