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The Cyber Defense Review

The Cyber Domain

By Alexander Crowther | July 31, 2018

Both the Department of Defense (DoD) and the North Atlantic Treaty Organization (NATO) have declared that cyber is a “domain”, co-equal with air, land, and sea. DoD also recognizes space as a domain. Merriam-Webster defines a domain as a sphere of knowledge, influence, or activity. [1] Although DoD does not define “domain”, it does define cyberspace as “A global domain within the information environment consisting of the interdependent network of information technology infrastructures and resident data, including the Internet, telecommunications networks, computer systems, and embedded processors and controllers.” [2] No one has yet proposed what the cyber domain is, where militaries should be operating in cyberspace, and what missions’ militaries should be doing in cyberspace. This article identifies what DoD says their missions are in cyberspace and discusses what areas are appropriate for military operations in cyberspace. Additionally, it argues that militaries must be very careful about what missions they accept in cyberspace, and must circumscribe their forays into cyberspace lest they are overwhelmed by the sheer scope of the domain.

The Cyber Domain


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