Multi-Domain Confusion: All Domains Are Not Created Equal

“The beginning of wisdom is the definition of terms.” —Socrates

Words matter. They frame thoughts and influence concepts by shaping perceptions, preferences, and priorities in the form of tacitly embedded assumptions.[1] Unfortunately, military conceptual frameworks are often encapsulated in jargon and buzzwords that periodically dominate the landscape of Pentagon briefing slides. Notable past examples of these operational concept catchphrases include: Active Defense, AirLand Battle, Full-Spectrum Dominance, Network-Centric Warfare, Effects-Based Operations, Anti-Access/Area Denial, and AirSea Battle. The latest conceptual phrase to command the spotlight is Multi-Domain Battle, which was officially unveiled by the US Army’s Training and Doctrine Commander, General David Perkins, at the Association of the U.S. Army’s Annual Meeting and Exposition on October 4, 2016.[2] This announcement was foreshadowed a month earlier in an article by Albert Palazzo and David P. McClain in which they touted “multi-domain battle will allow the joint force commander to dominate the targeted domains” because it “breaks down the traditional environmental boundaries between domains that have previously limited who does what where.”[3] The advent of multi-domain battle begs a question that remains unanswered: what constitutes a military domain and why make this distinction?


Over the past two decades the use of the word domain has attained wide acceptance in the military lexicon. Vague when described in doctrine, it exerts a strong influence by establishing the most basic boundaries of military functional identities. As described in an essay by Frank Hoffman and Michael Davies, domains “create a frame of reference that defines the preparation and conduct of war. Each military institution and Service crafts doctrine and platforms that are designed to operate or maneuver in their dominant domain. Little preparation is made to conduct war beyond them.”[4] Despite the unquestioned usage of domain-centric terminology, the exact meaning of domain remains largely undefined without consideration of etymological origins. However, the word contains some built-in assumptions regarding how we view warfare that can limit our thinking. An ambiguous categorization of separate operating domains in warfare could actually pose an intractable conceptual threat to an integrated joint force, which is ironically the stated purpose of multi-domain battle.

Prior to the concept of domains, military operations were typically described in only three physical dimensions of land, sea, and air. Following World War II, the National Security Act of 1947 formally established that military operations in these distinct physical dimensions required specialized knowledge and technical expertise which justified three separate functional departments. The notion of three physical dimensions became the basic organizing principle for the armed forces in three departments of Army, Navy, and Air Force: “In enacting this legislation it is the intent of Congress to provide a comprehensive program for the future security of the United States…to provide three military departments…to provide for their authoritative coordination and unified direction under civilian control but not to merge them; to provide for the effective strategic direction of the armed forces and for their operation under unified control and for their integration into an efficient team of land, naval, and air forces.”[5]


At the dawn of the 21st century, the notion of warfighting domains initially entered the joint lexicon through the notion of uncontested U.S. military supremacy. In 1996, the Chairman of the Joint Chiefs of Staff published a 34-page document entitled Joint Vision 2010. It was the first of what would become a series of future joint concept documents prescribing a conceptual template for how the joint force would fight in the 21st century. The concept represented a bold expression of the unipolar attitude of American exceptionalism following the end of the Cold War and the heady success of Desert Storm. The joint vision assertively defined “full-spectrum dominance” as the ability “to defeat any adversary or control any situation across the full range of military operations” and theorized about creating “asymmetric advantages by attacking cross-dimensionally.”[6]

In June 2000, the Joint Staff J-5 updated the previous concept to notionally cover another future decade. A revised document called Joint Vision 2020 further elaborated the notion of full-spectrum dominance which implied that “US forces are able to conduct prompt, sustained, and synchronized operations…with access to and freedom to operate in all domains – space, sea, land, air, and information.”[7] Thereafter, domain proved to be extremely catchy and quickly propagated, since the word is also commonly used to describe internet protocols. The nebulous fifth domain of information was recast as cyberspace, a decidedly more accessible term that also reflects the prominence of internet culture, as well as promises an exciting new technological frontier for warfare.

In 2009, the Capstone Concept for Joint Operations, Version 3.0 cemented a common taxonomy consisting of five equivalent domains of U.S. supremacy. The concept confidently envisioned how “joint forces maintain freedom of action on the land and sea and in the air, space, and cyberspace—in both the operational area and the global commons” while also acknowledging “a growing number of potential adversaries in the future will have the capability to contest U.S. domain supremacy as part of a strategy of erosion, not only in the air and maritime domains, but also on the land, in space, and in cyberspace.”[8]


The five-domain model that currently appears in joint concepts and doctrine is problematic because the construct denotes terrestrial ownership and implied uniformity that becomes a harmful metaphor when used indiscriminately. The use of domain carries a semantic implication of ownership, which is directly born from the notion of U.S. military preeminence. The word also has a distinct territorial origin that shares the same root as dominion and dominance from the Latin word dominium, which means “property, right of ownership.” The Merriam-Webster Dictionary defines domain primarily as “complete and absolute ownership of land.” Common synonyms include; realm, kingdom, territory, province, and fiefdom.


While the notion of sovereign ownership and control defended by military forces makes logical and legal sense on land, it tends to break down when applied to other areas. Beyond land our capacity for physical control due to environmental conditions is more dependent upon transient technical capabilities and less on persistent and actual human presence. The farther one travels away from land into the wide expanses sea-air-space, the notion of control or ownership becomes more tenuous, as well as legally problematic. The notion of sovereign dominion becomes more vehicular than territorial. The legitimacy of territorial waters and airspace exist only in proximity to land owned by a nation state. International waters and airspace, in addition to space and cyberspace, are considered global commons owned by no one, because there is no direct relation to land. National interests in these places involve ensuring access and freedom to operate rather than absolute ownership. Therefore, the notion of political dominion that describes occupying territory is not the same as safeguarding the right of use of the global commons that allows connectivity for communication and transportation. Metaphorically speaking—around domains we build walls to define and defend territory, whereas in the open spaces between, we guard bridges to ensure and control access.


Not only does the current five-domain model imply an unhelpful aspect of absolute ownership, but the arrangement also suggests that these domains are equivalent. It makes little sense to talk about fighting battles in the same manner across domains, if doing so doesn’t provide a compelling conceptual advantage. Moreover, if the nature of domains involves operations and effects that are fundamentally different, it could even be detrimental. This was not a concern when the military acknowledged only three dimensions of land, sea, and air. These basic physical distinctions are somewhat intuitive, since they loosely correspond to the three states of matter—solid, liquid, or gas. More importantly, in the context of military operations, the same physical characteristics can be applied to achieve kinetic material effects commonly described in terms of mass and maneuver.


However, the characterization of space and cyberspace as similar to earthly domains generates conceptual inconsistencies. Just as our sense of control diminishes as we travel beyond land, so do the desired effects we seek in order to influence a target. Our presence and ability to control becomes less physical and increasingly more virtual as we extend our influence over the seas, into the air, and overhead in space. The space environment includes some very unique physical characteristics, such as the lack of atmosphere, the peculiarity of orbital mechanics, and the persistent hazard of space debris, which make it quite unlike either sea or air. Although some aspects seem logically analogous, “such attempts to extend earthside experience to space often are misleading, sometimes spectacularly and dangerously so.”[9]

While it is technically possible to achieve physical effects from space, this is a politically contentious and strategically oriented issue that is arguably outside the bounds of conventional military operations. Therefore, the utility of space for military operations is predominantly derived from critical virtual enabling effects such as communication, surveillance, and navigation. This suggests that space is more of a quasi-domain in terms of the direct physical and kinetic effects that are more materially apparent via land, sea, and air. When one considers cyberspace as a man-made domain, the effects are almost completely virtual, which suggests that it shouldn’t be considered a domain in the same manner at all.[10] Rather, we should seek to understand cyberspace in its own terms and avoid “attempts to transfer policy constructs from other forms of warfare.”[11]


Despite these semantic shortcomings, domains are firmly entrenched in the military lexicon and will not be going away, even if the Secretary of Defense himself banned the use of the term.[12] A possible remedy involves establishing a doctrinal definition within an overall construct that clarifies and expands understanding of the operational environment. A fourth definition of domain appearing in the Merriam-Webster Dictionary is “a sphere of knowledge, influence, or activity.” This definition sidesteps the unwanted implication of physical ownership, and lessens the conceptual significance. Abstractly reducing the importance of domains by allowing for the designation of more domains may also reduce the tendency to create unwieldy and wasteful organizational stovepipes based on control of resources over function.

In order to minimize the problem of domain equivalence, a revised construct should distinguish different types of domains in relation to relevant and advantageous warfighting effects. Focusing on effects rather than domains would allow for the elimination of unnecessary bureaucratic seams, gaps, and turf wars. A possible construct can be found in a forgotten section of the Capstone Concept for Joint Operations, Version 2.0 released in August 2005. This version attempted to describe multiple domains as across “any potential operating ‘space’ through which the target system can be influenced—not only the domains of land, sea, air, and space, but also the virtual (information and cyber) and human (cognitive, moral, and social) domains.”[13]

Figure from Capstone Concept for Joint Operations, Version 2, page 16

The construct of three domain categories was abandoned in favor of the five-domain model that was reaffirmed in the following version. What the joint community lost was the notion of broad categories that distinguishes domains in terms of relevant effects. Land, sea, air, and space are physical domains involving material reality. Cyberspace and information, as well as the electromagnetic spectrum are virtual domains involving sensing and perception. The construct also included a human category involving value judgements. Hoffman and Davies argue that human-related aspects of warfare are not adequately addressed in joint concepts and doctrine.[14] The word social is perhaps a better label for this category, since human beliefs are reflected in social constructs and networks. More work needs to be done, but the idea of domain categories offers a promising model that could make the concept of multi-domain battle more workable by providing an overarching rationale for true joint integration.

The current conception of five warfighting domains has led the joint force into a conceptual cul-de-sac that undermines the ability to think holistically. The latest version of Joint Publication 3-0, dated 17 January 2017, describes the operational environment as “encompassing the physical areas of the air, land, maritime, and space domains; the information environment (which includes cyberspace); the electromagnetic spectrum; and other factors.”[15] The description of cyberspace as part of the information environment, inclusion of the electromagnetic spectrum, and the enigmatic explanation of ‘other factors’ can be regarded as a subtle acknowledgement of warfighting considerations beyond purely physical areas. What is needed is a simplified construct that defines domain as ‘an area of knowledge, influence, or activity by which a target system can be affected’ with reference to three overarching and interrelated warfighting dimensionsphysical, virtual, and social.

Erik Heftye is a retired Air Force officer and senior military analyst in the U.S. Army’s Mission Command Battle Laboratory at Fort Leavenworth, Kansas. The opinions expressed in this article are the author’s alone and do not reflect those of the U.S. Army, the Department of Defense, or the U.S. Government.

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Header image: Bodiam Castle, Wikimedia Commons


[1] Feist, T. (2016, November 7) War and the Treacheries of Taxonomy. War on the Rocks. Retrieved from

[2] Kimmons, S. (2016, October 5) “New multi-domain battle concept to drive change in Army’s future.” TRADOC News Center. Retrieved from

[3] Palazzo, A. & McLain III, D. P. (2016, September 15) “Multi-Domain Battle: A New Concept for Land Forces.” War on the Rocks. Retrieved from

[4] Hoffman, F. G. & Davies, M. C. (2013, June 10) “Joint Force 2020 and the Human Domain: Time for a New Conceptual Framework?” Small Wars Journal. Retrieved from

[5] U.S. Congress (1947, July 26) Public Law 80-253, National Security Act. National Archives and Records Administration. Office of the Federal Register. Retrieved from

[6] Joint Chiefs of Staff (1996, July) Joint Vision 2010. Washington, DC: US Government Printing Office, 21. Retrieved from

[7] Joint Chiefs of Staff (2000, June) Joint Vision 2020. Washington, DC: US Government Printing Office, 6. Retrieved from

[8] Joint Chiefs of Staff (2009, June) Capstone Concept for Joint Operations, Version 3.0 Washington, DC: US Government Printing Office, 26. Retrieved from

[9] Oberg, J. E. (1999) Space Power Theory. Colorado Springs, CO: US Air Force Academy, 2. Retrieved from

[10] Libicki, M. C. (2012, Fall) “Cyberspace is Not a Warfighting Domain,” Journal of Law and Policy for the Information Society 8 (2), 322. Retrieved from

[11] Libicki, M. C. (2009) Cyberdeterrence and Cyberwar. Santa Monica, CA: RAND, xiii. Retrieved from

[12] Mattis, J. N. (2008, Autumn) “USJFCOM Commander’s Guidance for Effects-based Operations,” Parameters 38, 18-25. Retrieved from

[13] Joint Chiefs of Staff (2005, August) Capstone Concept for Joint Operations, Version 2.0 Washington, DC: US Government Printing Office, 16. Retrieved from

[14] Hoffman, F. G. & Davies, M. C. “Joint Force 2020 and the Human Domain: Time for a New Conceptual Framework?”

[15] Joint Chiefs of Staff (2017, January 17) Joint Publication 3-0: Joint Operations. Suffolk, VA: Joint Staff J-7, IV-1. Retrieved from