Lethality: An Inquiry

The U.S. National Defense Strategy can be summed up in one word: lethality. “A more lethal, resilient, and rapidly innovating Joint Force, combined with a robust constellation of allies and partners, will sustain American influence and ensure favorable balances of power that safeguard the free and open international order.”[1] This vision is admirable and cogent, but the central tenet is never defined. What is lethality? Traditionally, lethality has been a tactical concept. We talk of lethal dose, lethal weapons, and lethal force. But in the National Defense Strategy lethality is strategically elevated. Deputy Secretary of Defense Patrick Shanahan’s recent tweet reinforced this ascension: “Everything we do is geared toward one goal: maximizing lethality. A lethal force is the strongest deterrent to war.”[2] Why?

Left undefined, lethality risks the fate of many insufficiently elucidated but well-meaning concepts. It is imperative the concept is properly understood, otherwise the word will saturate PowerPoint slides bereft of insight. Given the theoretical grounding it deserves, lethality provides incisive structure. It forms the backbone and guiding intent underwriting the litany of defense actions, processes, and programs: from doctrine, organization, training, and materials to leadership, education, personnel, and facilities. Understood tactically, organizationally, and strategically, lethality hones a latent ethos. Word choice matters, which is the point. The National Defense Strategy is a well-informed and insightful guiding document, but lethality deserves unpacking.

A History of Lethality

Lethality has not been a stable concept. George William Lemon’s 1783 "English Etymology- Or, a Derivative Dictionary of the English Language,” provides a sense of forgetfulness and death. The word derives from the Greek αηθη and Latin oblivio and initially evokes the sense of “causing spiritual death.” Today, the New Oxford American Dictionary defines lethality as “the capacity to cause death or serious harm or damage.” Common to each is a causal relationship with death, but Lemon’s etymology merely identifies the causality while ordinary usage separates out the causality as a latent capacity to cause death. We see this shift in the mid-nineteenth century, when lethality took on a particular medical connotation. Lethality was defined in contradistinction with mortality: the latter spoke to the notion that we are all going to die, while the former invoked the probability of imminent death. Eventual death is a necessary fact of humanity. Impending death is contingent on a particular state or condition, in this case disease. Unsurprisingly, this is the same sense with which Clausewitz uses tödlichen to describe “deadly illness.”[3] We will return again to this temporal distinction.

A look at the relative frequency with which the terms “lethal” and “lethality” appear in Google’s English-language corpus over time using Ngram. (Author’s Work/Google)

The growth in the use of lethal as terminology preceded that of lethality. The 1920s was an inflection point after which their use increased appreciably.[4] Prior to the First World War lethal remained a scientific description. As poisonous gas leached into the trenches, the concept breached military discourse. The concept applied more to the science of chemistry than the art of war. Lethal gas wafted into our lexicon as an entire generation was lost: αηθη; oblivio. During the interwar years the tendrils took hold. By the Second World War, mines were destructive to submarines within lethal range. The shift was spatial. The detonation of the atomic bomb extended that proximity to a lethal area. Lethal applied not to the object itself, but its physically defined potentiality.

Sharpness, a property shared by both knives and pencils, is necessary but not sufficient for their lethality. Intent actualizes lethal potential.

Trevor Dupuy’s 1964 “Final Report on Historical Trends Related to Weapon Lethality” codified the military appropriation of the concept. His team defined lethality as “the inherent capability of a given weapon to kill personnel or make material ineffective in a given period, where capability includes the factors of weapon range, rate of fire, accuracy, radius of effects, and battlefield mobility.”[5] The definition is limiting. First, lethality is not just “inherent capability.” Lethality is an emergent, intentional relationship between an object and the surface on which it is used. Tools possess properties that may or may not be potentially lethal. Whether a tool is a tool or a tool is a weapon depends on its use. Some tools, such as a knife, are predisposed or designed to be weapons. Others develop from specific contexts, like John Wick’s pencil.[6] Sharpness, a property shared by both knives and pencils, is necessary but not sufficient for their lethality. Intent actualizes lethal potential.

Tactical, Organizational, and Strategic Lethality

Tactical lethality requires tools, weapons, or dispositions that are potentially lethal. They must possess qualities that can make them lethal. They must be in a specific, technically determined, spatiotemporal relationship with the target. This is the capability to strike at which is aimed, what I call elsewhere tactical precision. This latent inexorable deadly relationship between a weapon and its effect makes it lethal. Russell M. Cantron’s August 1936 Marine Corps Gazette article, “A Study of Marine Corps Infantry Weapons,” is an early articulation of this relationship. He argues rifleman fall into two camps. Those who shoot well and those who do not. The experts deserve rifles to reinforce their precision. The rest should be issued shotguns. The point is to ensure all riflemen are tactically effective. “[A] lethal area is one in which the opposition cannot live.”[7] This does not mean the opposition may not reside within this area. The situation is such that if the expert rifleman chooses to fire then the enemy is shot. The causality is determined by the spatial, temporal, and intentional relationship between the rifleman, the weapon, and the enemy.

Improving tactical precision, and thereby tactical lethality, is a basic warfighting desire. As Lieutenant Commander Allan Glennon wrote in a September 1964 Proceedings article, “An Approach to Anti-Submarine Warfare,” “The lethal lane or radius for most weapons is not susceptible to easy enlargement; if it were, we would undoubtedly enlarge it.”[8] Secretary Mattis’ Close Combat Lethality Task Force is tasked to develop just this capacity: “Infantry squads require enhancements in organic lethality to prevail over pacing threats.”[9] The Task Force reflects the desire to create what Major General (Retired) Robert Scales describes as an “unfair fight.” This is like a tactical guillotine. To avoid a technical solution, the ambush exemplifies this same inevitability. It is as deterministic as possible without being determinism, for, just like humans, the guillotine can falter. Tactical lethality is not meant to be fair, in the balanced sense. It is a skewed relationship. These actions are not without risk; they are just unbalanced in our favor.

Organizational lethality emerges from tactical lethality that is institutionally codified.

New weapons, such as loitering munitions, help. They capitalize on Dupuy’s “factors of weapon range, rate of fire, accuracy, radius of effects, and battlefield mobility,” but parameter optimization does not entail efficacy.[10] Metrics matter, but the employment matters more. “[I]deas regarding the employment of weapons have been far more important than the weapons themselves.”[11] These ideas pertain to aggregate employment. For instance, the combined-arms dilemma expands the lethal area of any individual weapons by leveraging and interlacing multiple effects. Tactics, techniques, and procedures provide standardization to minimize coordination inefficiencies, while doctrine, buttressed by theory, governs the whole. Organizational lethality emerges from tactical lethality that is institutionally codified.

Imagine a spear. The sharp tip represents blatant tactical lethality. Given a certain spatiotemporal relationship the blade slices. However, the blade alone does not make a spear. The spear requires the shaft, which is not lethal itself unless used as a cudgel. The shaft creates the emergent lethality of the blade qua spear. It extends the lethal reach of the spearman. Moreover, the spear is more lethal than the blade because of the shaft.[12] It emerges from the hilt where the lethal and non-lethal properties combine as blade and shaft into a spear. The composition possesses more potential lethality than the blade itself. The organizational structure leverages the shaft’s length and translates it into power, amplifying the lethality of the blade. The Department of Defense is not one spear though. It is a diverse collection of blades and shafts, each of which must be forged together. Each weapon has a potentiality that must be trained individually and harnessed institutionally. Each weapon ought to remain sheathed until political guidance requires its potential lethality. For without political guidance, the arms do not matter.

Strategic lethality is the efficacy with which organizational lethality can be actualized toward the ends of that political guidance. This presupposes tactical lethality. It’s as if a Prussian couple concluded tactics is the act of combat, and strategy is its use. Strategic lethality also requires strategic accuracy. The efficiency is tied to a judgment about the instrumental value of using force in a certain way. Here there are two kinds of lethal latency. The first mirrors the same conditional, intentional relationship found in tactical lethality: the actual potential to affect, however so determined. This is Clausewitz’s threat, where “the possibility of future military action [is] based on the disposition of the forces at that time.”[13] The second is Schelling’s threat, where “we communicate to our opponent–be it through language or action–that if a certain something happens, then we will react in such a way.”[14] We have Clausewitzian capability coupled with Schelling’s communication to produce the National Defense Strategy’s required combat credibility. Strategic lethality is not sufficient for deterrence, but it is a part of the triptych.

Recall that tactical lethality is a latent, intentional, deadly relationship between an object and the surface on which it is used. Organizational lethality emerges from tactical lethality that is institutionally codified. Tactical lethality is nested within organizational lethality, which is nested within strategic lethality. Plugging these terms into an implicit calculus, we can rewrite strategic lethality as the efficacy with which we can form intentional deadly relationships towards targets that can be actualized towards political ends. Notice first that the organizational component becomes implicit. What remains outside, however, is the intention–a meta-intention–to form these potential deadly relationships in the first place.

Proclaiming lethality a core tenet, especially in a public strategic document, is the communication of the threat.

Strategic lethality cannot be sufficient for deterrence without added credibility based on identification of the threat against which it is acting, which comes from the National Defense Strategy document itself. This would beg the question if not for the external audience reading American military actions through a lethal lens, magnified by a focus on great power competition and from the political commitments of elected leaders informed by their interpretation of the public will.[15] Proclaiming lethality a core tenet, especially in a public strategic document, is the communication of the threat.


The clear and deliberate choice to include lethality in the National Defense Strategy reveals a deeper priority: credibility. This is a consequence of the responsibility to ensure the military is both efficient and effective, wasting neither money nor lives. Credibility requires the ability to back up threats one has, perhaps, not yet actualized; hence, we have the tension between modernization and readiness. Although lethality is deeply tied to the capacity to cause death, this does not mean tactical lethality is about killing more. Nor does it suggest organizational lethality is skewed to one service or one specialty, such as Special Forces. Strategic lethality must be founded on the trust and confidence the American public places in our forces to threaten violence and, when necessary, employ it. Lethality is not violence, however, even if it is necessarily violent when actualized. Lethality, like strategy, is about the future. It is a statement of imminent possibility. It is a sober reminder that war can be deadly. It alerts citizens and military members alike to be ready for a potential violent future, to steel our mettle and sharpen our steel.

Olivia A. Garard is an officer in the U.S. Marine Corps, an Associate Editor for The Strategy Bridge, and a member of the Military Writers Guild. The opinions expressed are the author’s alone and do not reflect those of the U.S. Marine Corps, the Department of Defense, or the U.S. Government.

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Header Image: Secretary of Defense James N. Mattis and Vice Chairman of the Joint Chiefs of Staff Air Force Gen. Paul J. Selva testify on the National Defense Strategy to the House Armed Services Committee (Navy Mass Communication Specialist 1st Class Kathryn E. Holm/DoD Photo).


[1] Secretary of Defense Jim Mattis, Summary of the National Defense Strategy: Sharpening America’s Competitive Edge, Department of Defense, January 2018, 1.

[2] Deputy Secretary of Defense Patrick Shanahan, @DepSecDef, Twitter Post, 29 September 2018, 2:56 P.M., https://twitter.com/DepSecDef/status/1046111464656957440.

[3] Clausewitz, 5.12. Using google translate and the search function on clausewitz.com, I determined tödlichen is used only once in Vom Kriege and used to refer to deadly illness. “Wieviel leichte Krankheiten werden dadurch zu schweren, wieviel schwere zu tödlichen!” Graham’s translation reads “How many trifling illnesses by that means become serious, how many serious ones become mortal.”

[4] Play around with the Google Ngram’s different smoothing levels and different English dialects. There are fascinating moments. It is unfortunate that it is bounded by the end of the aughts.

[5] Trevor M. Dupuy, “Final Report on Historical Trends Related to Weapon Lethality,” Historical Evaluation and Research Organization, (Washington DC, 15 October 1964): 7.

[6] This is dual-use technology.

[7] Russell M. Cantron, “A Study of Marine Corps Infantry Weapons,” The Marine Corps Gazette, August 1936, Vol 19.3, https://www.mca-marines.org/gazette/1936/08/study-marine-corps-infantry-weapons.

[8] LtCdr Allan Glennon, “An Approach to ASW,” Proceedings, September 1964, Vol 90/9/739, https://www.usni.org/magazines/proceedings/1964-09/approach-asw.

[9] Directive-type Memorandum 18-001 – “Establishment of the Close Combat Lethality Task Force (CCLTF),” March 16, 2018, Attachment 2, 7.c.2.

[10] Dupuy, 7.

[11] Dupuy, 40.

[12] This is SOF truth 5: “The operational effectiveness of our deployed forces cannot be, and never has been, achieved without being enabled by our joint service partners.”

[13] Olivia Garard, “The Threatening Space Between Nukes and Napoleon: Clausewitz vs. Schelling” The Strategy Bridge, 23 August 2016, https://thestrategybridge.org/the-bridge/2016/8/23/the-threatening-space-between-napoleon-and-nukes-clausewitz-vs-schelling.

[14] Ibid.

[15] Many thanks to Jim Golby for this point.