Military electromagnetic compatibility (EMC) is a matter of life and death as modern war-fighters rely on the safe, secure and reliable functioning of their devices.  Military EMC includes aspects of electronic interoperability that are seldom or never considered in the commercial realm.  This talk presents technical details of EMC consideration in tactical and strategic military operations. The topics discussed include hazards of electromagnetic radiation to ordnance (HERO), electromagnetic data security (EMSEC), counter improvised explosive device (CIED) EMC issues and includes first-hand experiences of work done in the Afghan theatre.