This publication, Field Manual FM 3-11 Chemical, Biological, Radiological, and Nuclear Operations May 2019, provides commanders and staffs with overarching chemical doctrine for operations to assess, protect, and mitigate the entire range of CBRN threats and hazards—including support to countering weapons of mass destruction (CWMD) activities in all operational environments. It addresses principles, fundamentals, planning, operational considerations, and training and support functions. It provides a common framework and language for CBRN operations and constitutes the doctrinal foundation for developing other fundamentals and tactics, techniques, and procedures detailed in subordinate doctrine manuals. This manual is a key integrating publication that links the doctrine for the CBRN units and staffs with Army operational doctrine and joint doctrine. The principal audience for FM 3-11 is commanders, staffs, and leaders of theater armies, corps, divisions, and brigades as well as CBRN units that integrate capability into those formations. However, FM 3-11 is applicable to all members of the profession of arms. To comprehend the doctrine in FM 3-11 readers must first understand the fundamentals of unified land operations described in ADP 3-0 and in FM 3-0. The reader must also understand the language of tactics and the fundamentals of the offense and defense described in ADP 3-90, and be familiar with operational terms and graphics described in ADP 1-02. Commanders and staffs of Army headquarters should also refer to applicable joint or multinational doctrine concerning the range of military operations (ROMO) and joint or multinational forces. FM 3-11 uses joint terms where applicable. Selected joint and Army terms and definitions appear in both the glossary and the text. Terms for which FM 3-11 is the proponent publication (the authority) are italicized in the text and are marked with an asterisk (*) in the glossary. Terms and definitions for which FM 3-11 is the proponent publication are boldfaced in the text. For other definitions shown in the text, the term is italicized and the number of the proponent publication follows the definition. FM 3-11 applies to the Active Army, Army National Guard/Army National Guard of the United States and United States Army Reserve unless otherwise stated.