Grey Zone: a theoretical concept and strategic tool of the West

Along with the concept of hybrid warfare, which we have already discussed in the previous report[i], the term "grey zone" (GZ) is actively used in the Western military-political community, has undergone the same transformation and has become used as a marker for opponents of the United States and NATO. Moreover, it has often been applied in Russia, as a rule, in relation to the conflict on the territory of Ukraine.

Let's look at what it was originally used for and why it was used as a synonym for hybrid warfare or its similarity.

The Special Operations Command of the US Armed Forces used the concept of GZ for its working documents. In particular, the US Special Operations Forces White Paper defines GZ as follows: "Grey zone challenges are defined as competitive interactions among and within state and non-state actors that fall between the traditional war and peace duality. They are characterised by ambiguity about the nature of the conflict, opacity of the parties involved, or uncertainty about the relevant policy and legal frameworks." [ii]

In a joint article written by two American generals and two other authors in the magazine Joint Force Quarterly No. 80, it was said that the GZ refers to the space of the continuum of peace and conflict.[iii] That is, it is not a well-defined state. Geographical boundaries are also omitted.

Many US military personnel and researchers also refer to the speech of the Commander of Special Operations, General Joseph Votel in the Senate on March 18, 2015. In this speech, the general noted that "actors taking a ‘grey zone’ approach seek to secure their objectives while minimising the scope and scale of actual fighting.

In this ‘grey zone’, we are confronted with ambiguity on the nature of the conflict, the parties involved, and the validity of the legal and political claims at stake. These conflicts defy our traditional views of war and require us to invest time and effort in ensuring we prepare ourselves with the proper capabilities, capacities, and authorities to safeguard U.S. interests.”[iv]

It has been argued that US special forces should play a special role both in resolving GZ crises and in interagency cooperation.

In Joint Force Quarterly No. 91, an author developing the topic of special operations in the GZ noted that "adversary nations will employ nonkinetic, psychological effects to enhance their more traditional military capabilities, employing them in tandem with conventional ground, maritime, and air forces or as the vanguard of aggressive military action against U.S. interests.”[v]

Other American experts have also noted that "trends such as globalisation, mass access to technology and communications, and asymmetric reactions to U.S. tactics in Afghanistan and Iraq are converging into an era where more and more conflicts are being fought at the lower end of the conflict spectrum. These form a ‘grey zone’ between traditional notions of war and peace.

Grey zone conflicts are not formal wars, and little resemble traditional, ‘conventional’ conflicts between states. If the spectrum of conflict is conceived as a line running from peaceful interstate competition on the far left to nuclear Armageddon on the far right, grey zone conflicts fall left of centre.

They involve some aggression or use of force, but in many ways their defining characteristic is ambiguity — about the ultimate objectives, the participants, whether international treaties and norms have been violated, and the role that military forces should play in response.

They can threaten critical U.S. interests through ‘strategic disruption’ — the danger that instability in key regions can upend the international political or economic order.

Traditional military capabilities remain essential for deterring and defeating threats at the higher end of the conflict spectrum, but effectively dealing with an era dominated by grey zone conflicts requires more. The best special operations forces in the world and more specialised conventional capabilities will both be necessary to fight and win in the grey zone.”[vi]

It was also emphasised that conflicts in the grey zone do not belong to a state of war or peace, but are located between them. In the coming years, they will be more frequent and complex.[vii]

Another definition says that "the grey zone is a conceptual space between peace and war, occurring when actors purposefully use multiple elements of power to achieve political-security objectives with activities that are ambiguous or cloud attribution and exceed the threshold of ordinary competition, yet fall below the level of large-scale direct military conflict, and threaten US and allied interests by challenging, undermining, or violating international customs, norms, or laws."[viii]

As a military theory, the monograph published by the US Army War College in April 2016 under the authorship of Antulio Echevarria II and entitled "Operating in the Grey Zone: An Alternative Paradigm for U.S. Military Strategy” is of interest. It speaks of the need to rethink the conventional type of war in connection with the dynamics of deterrence and coercion methods that have been effective for many decades before.

Antulio Echevarria II actually equates hybrid warfare with wars in the grey zone, while noting that they are not something new. Nevertheless, such a framework is necessary to point out the shortcomings of the military system and decision-making mechanisms in the West, adapt them to new challenges and develop a new flexible model that can be applied not only during a crisis, but also as a preventive measure.

The old concept of "operations outside the conditions of war" combined with sanctions, no-fly zones, air strikes and counter-terrorist raids can also be applied to the new conditions.[ix] The author notes that military strategists and campaign planners should plan their actions in such a way as to use the maximum number of dimensions to exert appropriate pressure, and it should be carried out for as long as it is necessary in order to achieve political goals.

In general, the overall vision of the US military's grey zone is that it needs to rethink the old approaches, more active interagency interaction and the use of military force to support political goals.

Following military analysts and practitioners, the topic of GZ is being developed by politicians.

In January 2017, the US State Department releases a report on conflicts in the grey zone, prepared by a group of international security advisers, a federal committee that provides the US State Department with its vision on public diplomacy, political-military developments, science, disarmament issues, etc.

It notes that although the term "conflict in the grey zone" is relatively new, the United States has repeatedly encountered this phenomenon and has repeatedly succeeded throughout its history.

It is indicated that the term GZ refers to the use of methods to achieve the goals of a nation and counter the goals of its rivals, using tools of power, often asymmetric and ambiguous in nature, which are not the direct use of recognised regular armed forces.[x]

The US State Department Committee acknowledges that what is now called GZ methods have in the past been conducted under such names as "political warfare”, "covert operations”, "irregular or guerrilla warfare”, "active measures”, and the like. In their view, in a sense, even the Cold War was one long campaign of the GZ on both sides on a global scale.

The central feature of GZ operations is that they involve the use of tools that go beyond normal international cooperation, but do not have explicit military force. They occupy the space between conventional diplomacy and commercial competition and open military conflict, and while they often use diplomacy and commercial action, GZ attacks go beyond the forms of political and social action and military operations that liberal democracies are familiar with to deliberately use the tools of violence, terrorism, and reprisal. In addition, they often include asymmetries in the magnitude of national interests or capabilities between adversaries.

GZ methods include:

- Cyber, information operations, efforts to undermine public/allied/local/regional resistance, as well as information/propaganda in support of other hybrid tools;

- Covert operations under state control, espionage, infiltration and subversion;

- Special forces and other state-controlled armed units, as well as unrecognised military personnel;

- Support - logistical, political and financial - for insurgent and terrorist movements;

- Involvement of non-governmental actors, including organised criminal groups, terrorists, and political, religious, ethnic, or sectarian extremist organisations;

- Assistance to irregular military and paramilitary groups;

- Economic pressures that go beyond normal economic competition;

- Manipulating and discrediting democratic institutions, including the electoral system and the judiciary;

- Calculated ambiguity, the use of hidden/unconfirmed operations, as well as deception and denial; and

- Overt or implicit threat or threats to use armed force, terrorism and abuses against the civilian population and escalation.

Later, expanded interpretations of the grey zone begin to appear, in particular its extension to the sea. At the same time, the concept is actively used by foreign partners of the United States. For example, the report "Grey zone operations and the maritime domain" published by the Australian Strategic Policy Institute in October 2018 stated that "maritime grey zone operations can be employed by a weaker power against a stronger power, but also by a stronger power against a weaker power or powers.

In the latter case, and as an important exception to the rule that escalation into kinetic exchanges is avoided in the grey zone, a stronger power may be willing to provoke a military response by the weaker power to make the latter appear to be the aggressor in a conflict it can then only lose."[xi] The report cites Russia and China as examples.

However, if the grey zone has political and economic dimensions, what role can the military play in this issue? As one of the American authors writes, "and grey zone approaches are undoubtedly aggression, in which military or paramilitary coercion is used, and the threat of escalation to outright conflict is often present. It follows that military tools must play a key role in any effective response.”[xii]

RAND Corporation is involved in the preparation of a number of studies and reports on the topic of the grey zone.

Michael Mazarr, Director of the Strategy, Doctrine, and Resources Program at the RAND Arroyo Center, frankly noted in one of his publications that "the real significance of grey zone campaigns is in their relation to the most fundamental challenge of the coming decades: finding a way to integrate rising, quasi-revisionist powers into the international order.”[xiii]

In other words, the GZ is a kind of synonym for the actions of states that do not accept the American world order and are trying to build a new system of international relations. It is no coincidence that the list of actors that exploit the grey zone constantly includes Russia, China and Iran — those countries that are most openly talking about the need to create a more just multipolar world order.

In 2019, in the collective work of RAND Corporation on the topic of GZ, attempts were made to, first and foremost qualify the concept itself. It says that "the grey zone is an operational space between peace and war, involving coercive actions to change the status quo below a threshold that, in most cases, would prompt a conventional military response, often by blurring the line between military and nonmilitary actions and the attribution for events."[xiv]

Eight characteristics of the grey zone are given. First, elements of the GZ remain below the threshold that would justify a military response. The second general characteristic of GZ activities is that they unfold gradually over time, rather than involving bold, all-encompassing actions to achieve goals in one step.

By extending aggressive movements over many years or even decades, such "salami tactics" provide less reason for a decisive response and, therefore, less ability to deter unambiguous threats in advance.

The third characteristic of the grey zone, which applies to some, but not all, activities in this zone, is the lack of attribution. Most GZ campaigns involve actions in which the aggressor seeks to conceal its role to at least some extent. Whether it's cyber attacks, disinformation campaigns, or proxy forces, these actions allow a grey-zone aggressor to deflect responses - and hinder potential successful deterrence - by simply denying responsibility.

Some actions in the GZ are open and definable. In these cases, they tend to be characterised by a fourth common aspect: the use of extensive legal and policy justifications, often based on historical statements supported by documentation.

Fifth, to avoid strong responses, GZ campaigns are usually short if they threaten the vital or existential interests of the defender.

An important quality of GZ campaigns is that they reflect a long series of limited fait accompli. They represent physical areas or problems with some power vacuum.[xv] 

The sixth characteristic of grey-zone aggression is that, even if it tends to stay below key thresholds for response, it uses the risk of escalation as a source of enforcement. Grey zone campaigns are designed to stay below the threshold for a large-scale military response, but they also, paradoxically, often explicitly hint at the risk of more violent military action, which provides escalation leverage and complicates deterrent threats.

Seventh, grey zone campaigns are usually built around non-military tools, which is part of the overall approach of staying below key response thresholds. They use diplomatic, informational, cyber, quasi-military forces, militias, and other tools and methods to avoid the impression of direct military aggression. To respond adequately, defenders must develop parallel public administration tools to threaten or execute deterrent threats.

Eighth, and finally, grey zone campaigns target specific vulnerabilities in target countries. This may include political polarisation; social divisions, including the existence of ethnic groups sympathetic to the aggressor of the grey zone; economic stagnation and the resulting needs and grievances; and the lack of military or paramilitary capabilities.

The authors believe that "measures of the Russian grey zone are usually divided into three categories:

1. influencing a specific outcome, such as an election or a dispute between Russia and the targeted state;

2. shaping the environment, which consists of creating conditions in a country for a national policy more favourable to Russia’s interests ;

3. punishing a state for taking actions that Russia perceives as offensive or contrary to its national interests; the idea is that such punishment should not only convey Russia’s displeasure but also, and more importantly, convince the targeted country’s leaders that such behaviours are not to be repeated.”[xvi]

Regarding China's actions in East and Southeast Asia, it says that "the types and drivers of these grey zone measures in the region, broken down along seven categories: military intimidation, paramilitary activities, co-opting of state-affiliated businesses, manipulation of borders, information operations, lawfare and diplomacy, and economic coercion."[xvii]

Another RAND study, also published in 2019, focused on possible "grey zone" tactics on the part of Russia in Europe.[xviii] To get closer to the real picture, simulation games were held, where three main actors acted - Russia, the EU countries and the United States. Russia attacked the vulnerabilities of the United States and its European partners, trying to undermine unity within NATO and expand its influence.

This report presents an innovation in methodology and assessment. "Identifying the grey zone as a tactic—rather than a type of conflict or operating environment—is a new approach, but one that has greater analytic coherence and is more useful for crafting civilian and military strategies to counter grey zone activities," the authors say.[xix]

GZ tactics, according to this study, include:

"1) Religious and cultural influence:

- promotion of Russian language and culture;

- expansion of Russian Orthodox Church;

- Use Russian Orthodox Church to intervene in political issues;

- Passportisation;

2) propaganda and information operations:

- Disseminate propaganda through state-controlled news channels;

- Create local media outlets to promote pro-Russian messages;

- False news and disinformation campaign;

- Amplify pro-Russian message with trolls and bots;

- Fund trolls and bots to take punitive actions against activists;

- Bribe or pressure journalists to influence content;

3) cyber operations:

- Hack sensitive or embarrassing information and provide to third parties to make public;

- Disrupt online communications and commerce through distributed denial of service (DDOS) attacks;

- Boost pro-Russian narrative through malware attacks;

- Disable or destroy infrastructure;

- Disseminate destructive malware to disable governments and industries;

4) support for proxies:

- Provide financial support to nongovernmental organisations (NGOs) to further entrench ethnic and social cleavages;

- Develop and sustain ties to criminal networks to earn money, gain intelligence, and act as Russian agents;

- Support paramilitaries and separatists;

- Provide financial support and publicity to political parties;

- Organise protests;

5) economic coercion:

- Secure controlling interest in critical economic sectors;

- Disrupt energy flows or complicate access to energy supplies;

- Embargo goods under false pretences;

6) Violent or military coercion:

- Unacknowledged military harassment;

- Create and sustain frozen conflicts as a source of persistent instability;

- Fuel civil war;

- Assassinate politicians, activists, journalists, and former officials opposed to Russian activities outside its borders;

- Attempt to oust uncooperative governments forcibly;

- Intimidate or detain journalists;

- Provide military cover to secession;

- Creeping borders".[xx]

It should be noted that the examples given by the authors of the study are in most cases not convincing, and the reference base of sources is questionable. However, in the context of the global information war waged by the West against Russia, there is a certain degree of probability that most of the accusations will be perceived by the majority of Western readers of this study with confidence and without any criticism.

In early January 2020, RAND Corporation released the following GZ-related study on Russia. It is called "Russia's Hostile Measures. Combating Russian Grey Zone Aggression Against NATO in the Contact, Blunt, and Surge Layers of Competition.”[xxi]

Based on the title of the monograph and its chapters, one can assess the degree of psychological effect that these titles can have. The authors clearly wanted to say that Russia as a political entity has an aggressive character, it has been so throughout history, and it will continue to be so in the future, so it is vital to prevent such aggressions in a variety of ways.

Of interest are the descriptions of the GZ itself, where Russia is active. Examples of Russia's bilateral relations with Moldova (1990-2016), Georgia (2003-2012), Estonia (2006-2007), Ukraine (2014-2016), and Turkey (2015-2016) are given as case studies in the GZ.

Therefore, under this approach, the GZs are independent sovereign states, including NATO members.

As for the methods attributed to Russia, there is a mix of economic restrictions imposed by Moscow for various reasons (for example, a ban on the import of wine from Moldova and Georgia), support for certain political parties, projects for relations with compatriots, diplomatic statements and sanctions (for example, against Turkey, when a Russian military plane was shot down over the territory of Syria).

As a result, it says that "our five cases may not stand alone as empirical evidence, but they are broadly exemplary of historical trends <...> Russia applies hostile measures successfully but typically fails to leverage tactical success for long-term strategic gain.”[xxii]

For several years, the Centre for Strategic and International Studies (Washington, DC) conducted a special project dedicated to the study of GZ.[xxiii] Several monographs and a number of articles on this topic have been published on the Centre's website. In one of them, John Schaus pointed out that "grey zone actions challenge U.S. interests, influence, or power and do so in ways designed to avoid direct U.S. military responses <…>

The United States should care because countries are using grey zone actions to undermine U.S. advantages, strengths, and interests. When China builds military outposts in international waters or when Russia uses non-uniformed soldiers to invade and attack a sovereign neighbour, it erodes confidence in a rules-based system <...>

In other words, grey zone activity by competitors like Russia, China, Iran, and North Korea can have real, tangible costs for U.S. interests,” the publication says.[xxiv]

The latest study, which was developed by five authors from the Center for Strategic and International Studies, was published in August 2019.[xxv] Unlike the previous report, where American experts tried to determine who poses a threat to the United States and its partners and how, this work focused on the response measures taken by the United States.

Participants in this process (competition in the GZ) from the United States are identified: the Department of Homeland Security, the State Department, the USAID Agency, the Department of Justice, the Department of Treasury, the Department of Energy, the Department of Defence and the Intelligence Community, and the International Development Finance Corporation.

NATO, US trade missions abroad, and independent agencies are also involved. An important role is played by the US Congress, which issues laws that provide targeted funding for the Department of Defence, the State Department, USAID, as well as a number of other structures aimed at interacting with the World Bank Group, the European Bank for Reconstruction and Development, etc.

It is also proposed to create a post of GZ intelligence officer and a Grey Zone Action Group (GZAG), which will deal with the following issues:

Specific directions and role clarity for agencies, with a regularised (e.g., monthly) deputies and principals committee process;
Strategic narrative in coordination with DHS, DoS, DoD, Intelligence Community (IC), and other implementing agencies;
Strategy, with implementing agencies, for allied and partner engagement and multilateral burden sharing;
Strategy, with implementing agencies, for private-sector engagement;
Particular focus on the nexus of cyber and information operations; and;
Encouragement for innovation and monitoring of progress and accountability.[xxvi]
It can be assumed that the Centre's recommendations were taken into account by those who make important political decisions in the United States.

The latest US Army Training and Doctrine Command booklet, published in October 2019, states that "our adversaries already are working to develop new methods and new means to challenge the United States. These efforts will only continue and attenuate through 2050. We can expect to encounter:

Multi-domain threats
Operations in complex terrain, including dense urban areas and even megacities
Hybrid Strategies/‘Gray Zone’ Operations
Weapons of Mass Destruction
Sophisticated anti-access/area denial complexes
New weapons, taking advantage of advances in technology (robotics, autonomy, AI, cyber, space, hypersonics etc.)
Information as a decisive weapon.”[xxvii]
In addition to weapons of mass destruction, all other items are somehow connected with both hybrid warfare and GZ.

In a special report on great power rivalry for members and congressional committees on March 4, 2021, hybrid warfare and GZ (countering them) are identified as one of the priorities for the Biden administration and the US Department of Defence, which should be taken into account when planning military spending.[xxviii]

An attempt to combine hybrid warfare and the grey zone under the guise of a new theory can be found in a publication by Justin Baumann, where he writes: ”Hybrid War Theory as a potential strategy to shape future generational doctrine for that grey zone and other unnamed areas of lethal and non-lethal competition which are important for US planners and strategists to design defeat mechanisms against potential adversaries operating in these areas.”[xxix]

So, the concept of the "grey zone" emerged as a theoretical construct among the Special Operations Forces, and then developed in the political and military-political communities of the United States. It has a broad interpretation and a clearly politicised context.

Based on the analysed publications, it can be concluded that the "grey zone" in the coming years will serve as a special label for any actions of certain states, primarily Russia, China, Iran and North Korea.

Regardless of what these actions are and how much they comply with the norms of international law, Western experts and politicians will always find an opportunity to accuse the leadership of these countries of conducting hostile actions in the GZ. Although the United States and a number of Western countries often carried out similar actions against other states and nations, they never fell into the category of GZ.

Admittedly, not all authors in the United States share this approach. In particular, Adam Elkus criticised the selective approach in choosing the GZ, asking why, for example, the terrorist activities of the Boko Haram group in Nigeria do not belong to the grey zone. He also pointed out that "the United States also utilises plenty of non-lethal coercive means — from financially ruining adversaries to deftly exploiting ‘lawfare’ to carry out strikes of often-ambiguous legal justification — to achieve its own aims.”[xxx]

Nevertheless, from an exclusively military and controversial term, the GZ has already become a kind of geopolitical marker that is used against opponents of the unipolar Pax Americana system, whether they are states or non-state actors.

[i] The concept of hybrid warfare: origins, application, counteraction https://russtrat.ru/node/6652

[ii] The US Special Operations Command, ‘The Gray Zone’, White Paper, 09 September 2015, p. 19 https://info.publicintelligence.net/USSOCOM-GrayZones.pdf

[iii] Joseph L. Votel, Charles T. Cleveland, Charles T. Connett, and Will Irwin. Unconventional Warfare in the Gray Zone

https://ndupress.ndu.edu/JFQ/Joint-Force-Quarterly-80/Article/643108/unconventional-warfare-in-the-grey-zone/

[iv]            https://docs.house.gov/meetings/AS/AS26/20150318/103157/HMTG-114-AS26-Wstate-VotelUSAJ-20150318.pdf P. 7.

[v] James E. Hayes III. Beyond the Gray Zone: Special Operations in Multidomain Battle. Joint Force Quarterly 91

https://ndupress.ndu.edu/Media/News/News-Article-View/Article/1681855/beyond-the-grey-zone-special-operations-in-multidomain-bat...

[vi] David Barno and Nora Bensahel, Fighting and Winning in the “Gray Zone”, May 19, 2015

https://warontherocks.com/2015/05/fighting-and-winning-in-the-grey-zone/

[vii] Nora Bensahel, Darker Shades of Gray: Why Gray Zone Conflicts Will Become More Frequent and Complex, February 13, 2017

https://www.fpri.org/article/2017/02/darker-shades-grey-grey-zone-conflicts-will-become-frequent-complex/

[viii] George Popp and Sarah Canna, The Characterization and Conditions of the Gray Zone, Boston, Mass.: NSI Inc., Winter 2016, p. 2.

[ix] Antulio J. Echevarria II. Operating in the Gray Zone: An Alternative Paradigm for U.S. Military Strategy, U.S. Army War College, 2016. Р. 22.

[x] International Security Advisory Board: Report on Gray Zone Conflict, January 3, 2017

https://www.state.gov/t/avc/isab/266650.htm

[xi]            https://www.aspistrategist.org.au/grey-zone-operations-and-the-maritime-domain/

[xii] Hal Brands, Paradoxes of the Gray Zone, February 5, 2016.

https://www.fpri.org/article/2016/02/paradoxes-grey-zone/

[xiii] Michael J. Mazarr, Struggle in Ithe Gray Zone and World Order, December 22, 2015

https://warontherocks.com/2015/12/struggle-in-the-grey-zone-and-world-order/

[xiv] Lyle J. Morris, Michael J. Mazarr, Jeffrey W. Hornung, Stephanie Pezard, Anika Binnendijk, Marta Kepe. Gaining Competitive Advantage in the Gray Zone. Response Options for Coercive Aggression Below the Threshold of Major War, 2019. Р. 8.

[xv] Ibidem. P. 10.

[xvi] Ibidem. P. 15.

[xvii] Ibidem. P. 27.

[xviii] Stacie L. Pettyjohn, Becca Wasser. Competing in the Gray Zone. Russian Tactics and Western Responses, RAND Corporation, Santa Monica,2019.

[xix] Stacie L. Pettyjohn, Becca Wasser. Competing in the Gray Zone. Russian Tactics and Western Responses, RAND Corporation, Santa Monica,2019. P. 9.

[xx] Ibidem. P. 14 - 18.

[xxi] Ben Connable, Stephanie Young, Stephanie Pezard, Andrew Radin, Raphael S. Cohen, Katya Migacheva, James Sladden. Russia's Hostile Measures. Combating Russian Gray Zone Aggression Against NATO in the Contact, Blunt, and Surge Layers of Competition, RAND Corporation, Santa Monica,2020. https://www.rand.org/pubs/research_reports/RR2539.html

[xxii] Ben Connable, Stephanie Young, Stephanie Pezard, Andrew Radin, Raphael S. Cohen, Katya Migacheva, James Sladden. Russia's Hostile Measures. Combating Russian Gray Zone Aggression Against NATO in the Contact, Blunt, and Surge Layers of Competition, RAND Corporation, Santa Monica,2020. P. 49.

[xxiii] At the time of publication of this material, the mentioned project has not yet been completed.

[xxiv] John Schaus. Competing in the Gray Zone. October 24, 2018

https://www.csis.org/analysis/competing-grey-zone-0

[xxv] Melissa Dalton, Kathleen H. Hicks, Lindsey R. Sheppard, Alice Hunt Friend, Michael Matlaga, Joseph Federici. By Other Means Part II: Adapting to Compete in the Gray Zone. Washington, DC: Center for Strategic and International Studies, August 13, 2019

https://csis-prod.s3.amazonaws.com/s3fs-public/publication/Hicks_GrayZone_II_interior_v8_PAGES.pdf

[xxvi] Ibidem. P. 44.

[xxvii] The Operational Environment and the Changing Character of Warfare. TRADOC Pamphlet 525-92. Department of the Army Headquarters, United States Army Training and Doctrine Command Fort Eustis, Virginia. 7 October 2019.

[xxviii] Renewed Great Power Competition: Implications for Defense—Issues for Congress. Congressional Research Service. March 4, 2021. Р. 15. https://fas.org/sgp/crs/natsec/R43838.pdf

[xxix] Justin Baumann. Using Hybrid War Theory to Shape Future U. S. Generational Doctrine. 02/03/2021

https://smallwarsjournal.com/jrnl/art/using-hybrid-war-theory-shape-future-u-s-generational-doctrine

[xxx] Adam Elkus, 50 Shades of Gray: Why the Gray Wars Concept Lacks Strategic Sense. December 15, 2015

https://warontherocks.com/2015/12/50-shades-of-grey-why-the-grey-wars-concept-lacks-strategic-sense/