July 2011 This publication provides tactical-level commanders and staffs with keystone doctrine for operations to prevent, counter, defend, and mitigate the entire range of chemical, biological, radiological, and nuclear (CBRN) threats, hazards, and effects-including support to combating weapons of mass destruction (CWMD) activities in all operational environments. It addresses operational concepts, principles, fundamentals, planning, operational considerations, and training and support functions.