Military Strategy Magazine  /  Volume 5, Issue 1  /  

How Should We Think about “Gray-Zone” Wars?

How Should We Think about “Gray-Zone” Wars? How Should We Think about “Gray-Zone” Wars?
To cite this article: Echevarria, Antulio J. II, “How Should We Think about “Gray-Zone” Wars?,” Infinity Journal, Volume 5, Issue 1, fall 2015, pages 16-20.

© Andreykr | – Russian Soldiers On March In Perevalne, Ukraine Photo


Whatever its origins, and whether it is a blessing or a curse or both, the expression living in “interesting times” certainly describes strategic life in the present day. Recent events in Ukraine, Syria, Iraq and the South China Sea, for instance, continue to take “interesting” turns. We could say the same of the various ways in which military force has been used of late. Analysts, practitioners, and scholars alike have struggled to come to terms with such uses, assigning labels such as “hybrid wars,” “new generation wars,” and “gray-zone” conflicts, among others, to distinguish contemporary practices from those of so-called traditional wars. While the original aim of such labeling or relabeling may have been to draw the attention of busy policymakers to emerging security issues, it has evolved into something of a culture of replication in which the labels are repeated more out of habit than reflection. As a result, we have an increase in claims about what contemporary wars are (or are not), but little in the way of strategic analysis to support those claims. This article avoids that trend by identifying the problem posed by so-called gray-zone wars, and suggesting how the West’s military strategists and campaign planners ought to adjust their conceptual frameworks to accommodate them.

What makes gray-zone wars “interesting” is they sit below NATO’s Article 5 threshold, and below the level of violence necessary to prompt a UN Security Council Resolution. Examples are the aggressive moves undertaken in recent years by Moscow in Ukraine and by Beijing in the South China Sea. In each of these cases, there was little or no legal premise for a military response by the West; hence, the tendency to refer to such hostile actions as gray-zone wars, that is, uses of military force that fall short of actual war but which definitely do not qualify as peace. Moscow and Beijing have been able to exploit this zone of ambiguity to accomplish “wartime-like” objectives outside the normal scope of what military strategists and campaign planners are legally authorized or professionally trained to address. Figure 1, which shows how the level of military effort is expected to increase and decrease over the course of a typical campaign, depicts this problem graphically.

Figure 1

Accordingly, gray-zone wars would appear to take place within the space or gap that precedes traditional military campaigning.[i] Moreover, they were likely designed this way intentionally. Nor are they “wars,” per se, as much as they are the outgrowth of strategies aimed at exploiting the West’s legalist view of war and its inherent restraints. Clearly, Western military strategists and campaign planners need an alternative model by which to develop strategies and campaign plans for such conflicts. In short, they need to think in terms of campaigns that can be conducted, with appropriate approval, below the thresholds mentioned above. What might the new campaigning model look like?

It is important to note the operational phases depicted in Figure 1 are currently under revision. Whenever the new doctrine is published, it may not have the same phases or even the same number of them. In fact, it likely will not; however, that is immaterial. The schematic of operational phases, referred to by some insiders (less than affectionately) as the “sand chart,” merely serves as a reference point, a way to visualize the problem.

One way to approach the problem of gray-zone wars is to reduce the hostile actions undertaken in Ukraine and the South China Sea to their core dynamic – which is a combination of coercion and deterrence. As Clausewitz once said, war is the use of force to compel an opponent to do one’s will.[ii] War, he believed, was basically coercion by violent means. Obviously, peace can also involve coercion, diplomatic and otherwise, but presumably with less bloodshed. What distinguished war from peace, in Clausewitz’s view, was simply the explicit use of coercive violence. Moreover, when we consider Clausewitz’s On War holistically, particularly his discussion of the defense in Book VI, we find that his understanding of coercion included a necessary complement, namely, deterrence. The defense is stronger than the attack because, in theory, deterring one’s foes is easier than coercing them. However, in practice the two are essentially opposite sides of the same coin: we are attempting to make others do what we want, while at the same time dissuading them from doing what we do not want.

Furthermore, we can find the coercion-deterrence dynamic in virtually every type of war. The exception that proves the rule is a genocidal war because it is aimed not at coercing a population but eradicating it. Even ethnic cleansing (which differs in nature from genocide) is at bottom about driving a people from a territory, and essentially involves using both coercive and deterrent force.

However, the dynamic is also present in situations short of war. Between 1936 and 1939, for instance, Adolf Hitler’s willingness to risk war – juxtaposed against the allies’ desire to preserve peace – made his use of coercive force and diplomacy quite effective. We might call it coercive diplomacy today, though the term was not in vogue at the time. Instead, it was more likely to be called “armed diplomacy,” or “gunboat diplomacy” in maritime situations.[iii] Hitler’s brand of armed or coercive diplomacy used an expanding military force (Wehrmacht), which was nonetheless already obsolete in important ways (such as many of its tanks), to exert both deterrent and coercive pressure: the idea of going to war, even with demonstrably favorable odds, was so uncomfortable to British and French diplomats they could be intimidated by Hitler.

One answer for dealing with gray-zone wars, therefore, is to design operations and campaigns around this dynamic, that is, around the basic idea of coercing or deterring foes or rival powers. Peacetime coercive operations might include activities such as mobilizing military forces, initiating training exercises along a border, conducting aircraft over-flights, or launching an overt show of force in nearby territories, arms transfers, and intelligence sharing. Actions once referred to as “military operations other than war” might also constitute coercive or deterrence operations; these include: enforcement of sanctions, implementation of no-fly zones, strikes and raids, among others.[iv] Such uses of force are sometimes necessary to establish credibility or to demonstrate resolve; key elements in the success of any coercive or deterrence operations.

How might such operations apply to the situation in Ukraine? The West might elect to deter further Russian (or separatist) aggression in specific areas of Ukraine, for instance, while also compelling Moscow to withdraw and to relinquish some of the territories they have already taken. One step toward accomplishing that aim would be to provide Ukrainian troops with qualitatively superior military hardware, and in enough numbers, so Ukrainian units are capable of inflicting significantly higher casualty rates on hostile forces than they themselves incur. The battlefields in Ukraine are high-tech in many respects, and the speed and range of one’s weapons actually matter a great deal. Furthermore, operations to supply Ukrainian troops with specific kinds of high-tech weapons would dovetail with the West’s imposition of economic sanctions because doing so would compound the costs of Moscow’s aggression. At some stage, so the theory goes, Moscow will find the war untenable economically and begin suing for peace. Thus, a strategy aimed at hastening the arrival of that moment would seem worthwhile. In any case, the point is, even in gray-zone wars, operations designed to coerce or deter opponents can support campaigns, which in turn support military strategies, which subsequently aim at achieving policy objectives.

Such operations need not involve physical combat on the part of US and other NATO and non-NATO partners if that is not desired. Their military strategists and campaign planners can have a hand in designing and orchestrating such operations regardless. In many gray-zone situations, military hardware, advisors, and intelligence support may be all that is permitted legally. Nonetheless, the West has most of the planning tools it needs. The key to success is to think of ambiguity as an opportunity and to use it to one’s advantage by ensuring military support to a beleaguered party is not haphazard and is well integrated into a larger plan.

To be able to do that, however, the West’s military strategists and campaign planners need to study the strategies of coercion and deterrence closely because each has important limitations. As stated above, coercion is usually understood to mean compelling people to do something, such as surrender; whereas deterrence is commonly defined as getting people to decide not to do something, such as continuing to fight as guerrillas.[v] Moreover, making our adversaries elect to do something (coercion) is closely related to making them choose not to do something else (deterrence). Coercive strategies typically include such measures as punishment, denial, intimidation, and reward. These have been used for centuries. Rome’s legions executed many punitive actions designed to coerce opponents rather than to annihilate or enslave them. Punishment might have been severe in some cases, but ultimately Rome wanted tribute, not ruins. Medieval wars, as well, often aimed at coercing foes through military actions designed to punish or deny, such as taking livestock, burning crops, or imposing levies.

Although coercive strategies have been in use for centuries, serious study of them did not begin until the 1950s and 1960s. The two pioneers in this regard were political scientist and national security analyst Robert E. Osgood and the Harvard economist, game theorist, and Nobel Prize winner, Thomas C. Schelling. As Osgood, a veteran of the Second World War, noted: “The purpose of war is to employ force skillfully in order to exert the desired effect on an adversary’s will along a continuous spectrum from diplomacy, to crises short of war, to an overt clash of arms.”[vi] To this view, Schelling added the argument military force could not only shape an adversary’s behavior short of all-out war, it could be applied in “controlled” and “measured” ways to compel, intimidate, or deter. “The power to hurt,” Schelling claimed, “is bargaining power. To exploit it is diplomacy – vicious diplomacy, but diplomacy.”[vii] Its purpose is to alter an opponent’s behavior without having one’s own conduct modified too greatly in the process.[viii] This view comes to form the basis for the “bargaining model” of war in which military power is seen as a form of currency to be expended in a process of violent bartering.[ix] It is a view well suited for gray-zone wars, though strategists would need to remember the currency of exchange is actually lives, not coins.

Coercion and its complement, deterrence, thus both require viewing diplomacy and war as a “continuous spectrum” rather than as an endeavor bifurcated along political and military lines. Unfortunately, as stated earlier, today’s spectrum of conflict is partitioned for legal, doctrinal, or bureaucratic reasons. While those boundaries must be respected as far as military actions are concerned, they are no justification for ceasing military planning and strategizing. To be sure, the partitions render the West vulnerable to exploitation by rival powers. However, the task of the strategist is to find workarounds that are both legally and politically acceptable. Common sense suggests the West could remove its self-imposed partitions, if it wished, or at least adjust them so they are less limiting. Nonetheless, doing so would be extraordinarily difficult because those partitions serve a number of vested interests tied to the West’s values. A change in those values is not likely to occur short of an existential threat, which by design, neither Russia nor Beijing is posing.

Coercion and deterrence have many of the same limitations. Both require active monitoring of potentially fluid situations, credible communications across cultural and psychological boundaries, and at least some shared expectations regarding the use of force. Like most other strategies, both coercion and deterrence are vulnerable to mirror-imaging, or projecting one’s values and ways of thinking onto one’s adversaries. Such projections lead to risky assumptions about what one’s rivals hold dear and how they will behave.

In theory, coercive strategies offer us more flexibility and greater control over escalation than military strategies such as attrition or annihilation. We can, for instance, apply coercive force gradually in what is known as “graduated pressure,” an approach tried by US Presidents James Polk in the Mexican-American War (1846-1848) and Lyndon Johnson in the Vietnam War. Each applied force incrementally, increasing its intensity in steps or phases with the aim of bringing their opponents to the negotiating table. The idea was to avoid committing more military power than necessary, or more than the American public would abide. However, each ran into difficulty because their respective opponents’ pain threshold was higher than anticipated, which in turn meant the amount of coercive force had to be increased beyond what was expected.[x] As one historian noted with regard to the war in Vietnam, “The level of pain Hanoi was prepared to endure was greater than Washington could inflict.”[xi]

To be sure, applying coercive pressure gradually may help achieve one’s objectives at minimal cost; however, it can also prolong the struggle and increase one’s losses until war weariness sets in and the public demands an end to the conflict. Friction and human emotion can also make it difficult to measure and control the level of force one employs, thereby potentially leading to escalation.

In addition to these limitations, deterrence has several others that are unique to it. A military strategy of deterrence requires making our adversary believe we have the physical and psychological capacity either to defeat an act of aggression, or to make its costs exceed its benefits. International relations literature currently recognizes four types of deterrence: (a) direct, which refers to deterring an attack against oneself; (b) extended, or deterring an attack against a friend or ally; (c) general, or deterring a potential threat; and (d) immediate, which refers to deterring an imminent attack.[xii] These are usually combined in some way. For instance, French and British efforts at immediate and extended deterrence on behalf of Poland failed to dissuade Adolf Hitler from invading that country on September 1, 1939.

First, it can be difficult to assess how well a strategy of deterrence is working. It is not always possible to know whether the absence of a rival’s action was because of deterrence, or despite it. As former US National Security Advisor, Henry Kissinger, once noted:

Since deterrence can only be tested negatively, by events that do not take place, and since it is never possible to demonstrate why something has not occurred, it became especially difficult to assess whether the existing policy was the best possible policy or a just barely effective one.[xiii]

Second, deterrence is inherently fragile. It is based on a balance of power – in technological, military, political, and diplomatic dimensions – that can change quickly, and give one party a decisive advantage over the other. Or, one party may feel it is losing parity and must act before it is too late. Consequently, deterrence can have a short shelf-life. For that reason, it is useful to think of deterrence as a delicate balancing act requiring constant attention.

Third, as with any military strategy, deterrence requires knowing one’s adversaries, especially since not all would-be aggressors can be deterred. Some, like Adolf Hitler, could be delayed, but not truly deterred; whenever they hesitated, they did so only long enough to gain a better advantage. Additionally, “suicide bombers” may have challenged the rational-actor model of deterrence in recent years. One way of coping with such actors is by denying them the conditions they require for success, such as by hardening defenses and dispersing likely targets so as to reduce casualties and make the attack less attractive.[xiv] Deterrence also works best when the parties share a baseline of expectations. Each party needs to be able to “read” the motives and actions of its rival; otherwise, profound misunderstandings may occur that lead to undesirable actions.

Finally, deterrence is vulnerable to friction and chance. Accidents, large or small, always happen. It can be difficult to determine whether such accidents were truly accidental; was the military aircraft that crossed another’s borders simply lost, or was it on a special mission? How parties respond to accidents or unforeseen events can easily upset deterrence, particularly if efforts at communication are misperceived; this is especially true of nuclear deterrence. Communication is, of course, vital, but cultural and psychological filters can act like a form of friction and distort one’s intended message. That is not to say ambiguity is never beneficial in strategy. Sometimes it can be useful to keep rivals guessing as to where one stands. Ambiguity is, in fact, one of the principles underpinning the 1979 Taiwan Relations Act, which clearly stated the United States did not support Taiwan independence, but also laid the groundwork for a “robust unofficial relationship” between the two parties.[xv]

Beijing’s particular approach to gray-zone wars involves a form of direct deterrence. It consists of positioning several hundred land-based, anti-ship ballistic and cruise missiles in a manner that could deny or restrict the movement of other countries’ naval vessels within the East China and South China Seas. Beijing may well view its strategy as “counter-intervention” or “peripheral defense,” since it is designed to prevent other powers from interfering in off-shore areas the Chinese see as vital to their interests.[xvi] In contrast, the Pentagon refers to this strategy as “anti-access/area-denial,” or A2AD, since it hampers Washington’s ability to provide extended deterrence for its allies in the region. Beijing’s counter-intervention strategy includes not only the use of modern air and missile technologies, but also what the Chinese call “political warfare,” which entails refuting the lawfulness of any interventionist acts (also known as law-warfare or “lawfare”), the mobilization of public opinion against an intervention, and psychological warfare.

In response, the United States and its allies have considered employing their own A2AD strategy, one that would restrict the movement of Chinese and North Korean vessels within the Western Pacific Region.[xvii] If implemented, the West’s countermove will result in overlapping missile and aircraft defensive zones along the Pacific Rim. Yet, the West can also do more by strengthening its alliances in the region, and by conducting more coercion and deterrence operations. A word of caution is in order, however, since implementing either strategy can lead to an arms race. Defined simply, arms races are efforts to keep pace with, or surpass, an adversary’s military might. History, in fact, shows arms races are often the outgrowth of the coercion-deterrence dynamic. The salient question, then, is whether the West believes its collective economic power is sufficient to win such a race, and whether it wants to accept the risk of doing so.

In sum, the coercion-deterrence is a useful way to approach gray-zone wars. Military strategists and campaign planners can develop options around this dynamic. Their courses of action can look to exploit the ambiguity of such wars, while remaining within their legal and political restraints. Conceptually, the result would be a new “sand chart” that might look something like Figure 2.

Figure 2

In truth, we might use any number of ways to depict the changes graphically. The goal is really to slide the military strategist’s orientation further to the left of the diagram, and to become experts at conducting our own “gray-zone” campaigns to coerce or deter, or both, before we must begin shooting (though indigenous forces may already have). One difference worth mentioning in Figure 2 is that “deterring activities” remain, but are to be expanded; while “shaping activities” are replaced by “coercing activities,” which are also to be expanded.

The larger point is, under current conditions, both of these strategies need to become more prominent features in the military strategist’s “tool kit.” Political leaders and diplomats will rarely have the training or time to study these strategies thoroughly and become experts in their use. Thus, it falls to military professionals to revise their doctrine and thinking appropriately and to train themselves to describe such activities in terms of formal courses of action. If we do not do so soon, we will continue to find ourselves at a disadvantage in responding to the coercive-deterrence activities of our rivals.


[i] Joint Publication 5-0, Joint Operational Planning (Washington, DC: US Govt. Printing Office, 2011), p. III-39; see also Antulio J. Echevarria II, “On America’s Way of Battle,” War on the Rocks, September 22, 2015.
[ii] Clausewitz, On War, 75.
[iii] Alexander L. George, Forceful Persuasion: Coercive Diplomacy as an Alternative to War (Washington, DC: US Institute of Peace, 1997); Daniel Byman and Matthew Waxman, The Dynamics of Coercion: American Foreign Policy and the Limits of Military Might (Cambridge: Cambridge University, 2002).
[iv] Joint Doctrine for Military Operations Other Than War, Joint Publication 3-07 (Washington, DC: US Govt. Printing Office, 1995). The acronym MOOTW was popular in the 1990s, but has since fallen out of vogue; the operations it describes continue under various names.
[v] For more see Thomas C. Schelling, Arms and Influence (New Haven: Yale University, 2008), 69-79.
[vi] Robert E. Osgood, Limited War: The Challenge to American Strategy (Chicago: University of Chicago, 1957); and Limited War Revisited (Boulder: Westview, 1979).
[vii] Thomas C. Schelling, Arms and Influence (New Haven: Yale University, 1966), 2, 16, 34.
[viii] For more see Lawrence Freedman, ed., Strategic Coercion (Oxford: Oxford University Press, 1998); Gordon A. Craig and Alexander L. George, Force and Statecraft: Diplomatic Problems in Our Time, 2d Ed., (Oxford: Oxford University, 1990).
[ix] Thomas C. Schelling, The Strategy of Conflict (Cambridge: Harvard University, 1960), 5; see also Oran Young, The Politics of Force: Bargaining during International Crises (Princeton: Princeton University Press, 1968).
[x] Wayne Thompson, “Operations over North Vietnam, 1965-1973,” in John Andreas Olsen, ed., A History of Air Warfare (Washington, DC: Potomac, 2010), 107-26; Gian Gentile, “The Chimera of Success: Pacification and the End of the Vietnam War,” in War Termination, 225-35.
[xi] George Herring, “America and Vietnam,” Foreign Affairs, 119.
[xii] Paul K. Huth, Extended Deterrence and the Prevention of War (New Haven: Yale University, 1991).
[xiii] Henry Kissinger, Diplomacy (New York: Simon & Shuster, 1994), 608.
[xiv] Alex S. Wilner, Deterring Rational Fanatics (Philadelphia: University of Pennsylvania, 2015), 4-7; Matthew Kroenig and Barry Pavel, “How to Deter Terrorism,” The Washington Quarterly 35, no. 2 (Spring 2012): 21-36.
[xvi] Experts disagree on the proper terminology for the strategy; compare: M. Taylor Fravel and Christopher P. Twomey, “Projecting Strategy: The Myth of Counter-Intervention,” Washington Quarterly 37, no. 4 (Winter 2015): 171-87, and Michael Carl Haas, “China: Exit Counter-Intervention, Enter Peripheral Defense,” Diplomat, March 4, 2015;
[xvii] Terence Kelly, Anthony Atler, Todd Nichols, Lloyd Thrall, Employing Land-Based Anti-Ship Missiles in the Western Pacific, Santa Monica, CA: RAND, 2013.