FIGHTING IN THE ELECTROMAGNETI

"At the beginning of the 20th Century, naval warfare, which for centuries had been limited to the surface, moved quickly into the domain below the surface and the air above. The influence of undersea and aerial warfare in naval history is well known. The fourth domain involving the electromagnetic spectrum, which also appeared at this time, also had an impact on naval warfare, though much less has been written about this important aspect of military conflict on the high seas. When navies began to make use of the airways, they soon discovered that it could also be used as a unique source of information about the opposing force, instituting a form of intelligence that would later be termed Electronic Intelligence. Also discovered was the value of interrupting or corrupting the enemy's communication signals that were transmitted in the ether, thus beginning a method of fighting we now term Electronic Warfare"--