Commanding the Electromagnetic and Cyber Environment


The electromagnetic (EM) spectrum is an unseen but integral part of our daily lives. Almost every one of us uses a remote (or EM transmitter) to control our television and unlock our car. We use mobile phones (or EM transceivers) to constantly stay in touch with each other by talking, e-mailing and texting. And, for more than a century we have relied on radio (or an EM receiver) and later television for news and entertainment. Important as the EM spectrum is in our personal lives, however, it is essential to our military operations. Failing to use it effectively can, no… actually it will be the difference between victory and defeat.

Now, we have also seen a merging in the last few years of the EM spectrum and cyberspace. High-bandwidth wireless networks in our homes, businesses and public spaces and satellite internet access for ships at sea and troops on the ground have made the electromagnetic spectrum an integral part of computer networks. Similarly, EM sensors such as radars and radiofrequency listening devices have become integral with the computer networks that control them and process their output.

This new EM and cyber environment presents us with challenges and opportunities in the 21st century similar to the undersea domain in the 20th century. Like the undersea domain, the EM and cyber environment is an area we can use to gain an advantage over our adversaries. To command this new environment, we need the ability to monitor and be aware of the environment, manage our emissions, discretely communicate, find, track and defeat threats, and conduct attacks as needed.

Today we are inextricably connected to the EM and cyber environment, and occasionally we conduct military operations in it. This situation parallels in many ways the period around the First World War, when submarines transited on the surface, preferred to submerge only to clandestinely move into firing position, and then surfaced to attack. In subsequent years, submarines spent more time submerged, and with the advent of nuclear power, no longer need to surface or snorkel. As a matter of survival, we developed an understanding of underwater acoustics and the ocean environment, a culture of sound silencing, and a doctrine of operating under water – eventually turning the undersea environment into a primary warfighting domain.

We need to make a similar advancement in our command of the EM and cyber environment. Our Sailors need to sense, understand and employ the EM and cyber environment in a similar way that submariners (officers and enlisted) eventually mastered acoustics and the undersea domain. Today we understand how specific adversary radars and communications systems work, emissions that indicate a threat or attack, which signals and techniques can defeat those EM systems, and the effects of the atmosphere on EM activity. But this knowledge and capability is discreetly inherent in different – but specific – systems and people, and is not managed in real time. Going forward we will develop the sensors and ability to pull all this information together coherently and continuously.

Our Navy’s undersea dominance resulted from the vision, discipline, and determination of Navy leaders and Sailors from World War I to today. They took a new and challenging domain and committed themselves to mastering it. However, they had the benefit of a clear technological and personnel advantage and built on their hard work and sustained investment.

We do not have such a clear advantage with regard to the EM and cyber environment. Unlike the undersea domain, most of the world uses the EM spectrum and cyberspace. Our potential adversaries can leverage commercial innovations to rapidly adapt and develop new capabilities. We need to tap into this same source of innovation. But we will also develop and leverage those strengths that are impossible to “reverse-engineer” – the skill and perseverance of our Sailors, the expertise and flexibility of our defense research base, our expanding international alliances and partnerships, and our history of adaptation and warfighting success.

We will further discuss this challenge and our efforts to command the electromagnetic and cyber environment in upcoming posts and articles. Stay tuned.

Admiral, U.S. Navy

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  • Mike Lambert

    Great post CNO. Would love to see more from you here. Responding to comments would make your blog more meaningful for everyone.
    Vr/Mike Lambert, Captain, USN – retired

  • John

    Admiral Greenert, thank you for some excellent material. You made a great and visionary case for recognizing and mastering the EM Domain in your article on Navy 2025 reported in Proceedings Magazine – December 2011 Vol. 137/12/1,306. The EM domain clearly underpins almost all other warfighting capability, in all the other domains. Mixing different domains such as cyber and EM only muddies the water, when clarity is essential, especially on the war-fighting bridge of a ship. There have been some related articles in the Journal of Electronic Defense which may be of some interest; I have written two. May I wish you and the US Navy all the best. John Clifford

  • Doug Karr


    I have a quick question about your blog, do you think you could email me?

    I look forward to hearing from you,


  • Charles Lilly

    Why did we dump NASA’s Shuttle Program @ $3 billion, leaving our EMP Satellites vulnerable to laser or atomic destruction, now we have to hitch a ride with the Russians to service our few secret satellites that are vital to communications, navigation and strategic mapping or watching potential enemy threats? I just can’t fathom the decision making for that one. Now we are going to privatize space? Sorry, I served in the USAF back when the Native Americans still had a foothold. I know that change is a constant and that’s why things constently change, but I am distressed over this decision. Was it the Joint Chiefs of Staff or the White House? I’ll bet you like to play chess, being a military maritimer, is this a good move or does your many Fleets have a backup plan? I am an old retired Engineer from NNS Reactor Plant and Planning Yard and NAVSEA at Carderock. I don’t know anything about space, but I’m counting on your Naval Research Lab antenna Engineers to tell me what they are doing these days. The World is getting more dangerous every day. I’m counting on you guys to serve and save our Nation. Then when you come home from duty you can be old and retired like me.