Book excerpt: Field Manual FM 3-12 (FM 3-38) Cyberspace and Electronic Warfare Operations April 2017 Over the past decade of conflict, the U.S. Army has deployed the most capable communications systems in its history. U.S. forces dominated cyberspace and the electromagnetic spectrum (EMS) in Afghanistan and Iraq against enemies and adversaries lacking the technical capabilities to challenge our superiority in cyberspace. However, regional peers have since demonstrated impressive capabilities in a hybrid operational environment that threaten the Army's dominance in cyberspace and the EMS. The Department of Defense information network-Army (DODIN-A) is an essential warfighting platform foundational to the success of all unified land operations. Effectively operating, securing, and defending this network and associated data is essential to the success of commanders at all echelons. We must anticipate that future enemies and adversaries will persistently attempt to infiltrate, exploit, and degrade access to our networks...