Office of Strategic Services (OSS) Manuals

This manual, published by the OSS during World War II, outlines practical methods for ordinary citizens to disrupt enemy operations using simple, low-risk acts. It emphasizes small-scale actions, such as wasting time, spreading confusion, and minor physical sabotage, that could cumulatively degrade enemy efficiency. Written for distribution in occupied territories, it demonstrates how even untrained individuals could contribute to resistance efforts. Today, it is studied as both a historical artifact and a primer on low-end disruptive tactics.

The Morale Operations manual guided OSS officers in psychological and propaganda campaigns designed to weaken enemy confidence. It provides detailed techniques for rumor-spreading, black propaganda, and other covert methods of undermining morale behind enemy lines. Unlike physical sabotage, its focus was on psychological impact, targeting perceptions, loyalties, and fears. It remains a foundational reference in the study of psychological operations and information warfare.

This OSS manual served as a comprehensive guide for training and conducting irregular warfare operations during World War II. It covers planning, organization, guerrilla tactics, demolitions, and coordination with resistance movements. The field manual reflects the OSS’s role as the forerunner of modern U.S. special operations forces, blending doctrine with practical fieldcraft. Today, it offers valuable insight into the evolution of unconventional warfare doctrine.

This manual provides an overview of the Office of Strategic Services’ internal structure, outlining the roles, responsibilities, and coordination of its various branches during World War II. It details how intelligence, research, and operations were organized to support the Allied war effort through centralized planning and field execution. The text captures the OSS’s evolution into a unified wartime intelligence organization, precursor to the modern CIA, and remains a key reference for understanding the origins of U.S. covert and special operations.

This manual documents the doctrine and methods of the OSS Maritime Unit, the forerunner of today’s naval special operations. It covers coastal infiltration, swimmer delivery systems, demolition techniques, and specialized maritime sabotage operations. Designed for operatives working behind enemy lines, it emphasizes stealth, adaptability, and innovative use of equipment in maritime environments. The manual reflects the OSS’s pioneering role in combining irregular warfare with naval tactics to enable unconventional operations from the sea.

This field manual outlines the organization, training, and mission of the OSS Operational Groups—elite, uniformed units conducting guerrilla warfare in occupied Europe. It provides guidance on small-unit tactics, coordination with resistance forces, demolitions, and intelligence integration. The document captures the OSS’s shift from clandestine support to direct action, illustrating how Operational Groups became precursors to modern U.S. Army Special Forces and established many of the principles of unconventional warfare still studied today .