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date: 24 January 2021

Peace: A Conceptual Surveyfree

  • Paul F. DiehlPaul F. DiehlSchool of Economic, Political, and Policy Sciences, The University of Texas at Dallas


Peace is an elusive concept with many different meanings. Traditionally, it has been equated with the absence of war or violence, but such “negative peace” has limited value as it lumps wildly disparate situations together, such as rivalries (India–Pakistan) and close political relationships (e.g., European Union). Nevertheless, this conception remains the predominant approach in theory, research, teaching, and policy discourse. “Positive peace” definitions are much broader and encompass aspects that go beyond war and violence, but there is far less consensus on those elements. Conceptions include, among others, human rights, justice, judicial independence, and communication components. Best developed are notions of “quality peace,” which incorporate the absence of violence but also require things such as gender equality in order for societies to qualify as peaceful. Many of these, however, lack associated data and operational indicators. Research on positive peace is also comparatively underdeveloped. Peace can also be represented as binary (present or not) or as a continuum (the degree to which peace is present). Peace can be applied at different levels of analysis. At the system level, it refers to the aggregate or global conditions in the world at a given time. At the dyadic or k‑adic level, it refers to the state of peace in relationships between two or more states. Finally, internal peace deals with conditions inside individual states, and the relationships between governments, groups, and individuals. Aspects of peace vary according to the level of analysis, and peace at one level might not be mirrored at other levels.


Our understanding of “war” is relatively straightforward. It is an event or series of events along a single military dimension. War is widely understood as a series of protracted military engagements between two or more parties with conflictual goals, resulting in some minimum number of casualties; operationally, the latter is often designated in the scholarly literature as somewhere between 25 and 1,000+ battle-related fatalities (Sarkees & Wayman, 2010). Many international relations theories, such as realism, often place war at their centers and focus primarily on the conditions for its existence or prevention. Furthermore, there are extensive and long-standing data collections that document war and militarized conflict over extended historical periods (Sarkees & Wayman, 2010). The use of terms such as the “war on terror” and the “war on drugs” are best understood as metaphors rather than an expansion of the concept. The bottom line is that an intersubjective consensus, within relatively narrow parameters, exists for the concept of war.

In contrast, peace is a far more amorphous concept, marked by considerably less common understanding in the scholarly literature and the popular mind. It is potentially a multifaceted idea that extends beyond military elements. Peace is also something that is better understood as an ongoing relationship rather than a single event (Goertz, Diehl, & Balas, 2016). Accordingly, a range of viewpoints exists on the fundamental characteristics of peace. Furthermore, it is under-theorized, and few data sets include measures of peace (at least explicitly so).

This article reviews the different conceptions of peace in academic studies, with an eye to identifying not only the range of views but also the commonalities and disagreements therein (see also Davenport, Melander, & Regan, 2018). Many works directly address peace as a concept, either as the focus itself or as a prelude to empirical analysis. Other analyses offer indicators of peace, but in doing so reflect an underlying conception of the term. In addition, conceptions of peace are reflected in theoretical formulations, empirical studies, and university courses on war and peace. This article reviews peace concepts in all these settings. Peace can be applied at different levels of analysis. At the system level, it refers to the aggregate or global conditions in the world at a given time. At the dyadic or k-adic level, it refers to the state of peace in relationships between two or more states. Finally, internal peace deals with conditions inside individual states and the relationships between governments, groups, and individuals. Aspects of peace vary according to the level of analysis, and peace at one level might not be mirrored at other levels. Nevertheless, conceptions are not always clear with respect to the level, and the review attempts to make these clear when possible.

As an organizing scheme, the article begins with some general considerations on concept development that frame some of the differences in the formulations that follow. It then follows the traditional distinction in the literature between “negative peace” and “positive peace,” respectively. The former simply refers to the absence of war or large-scale violent conflict, whereas the latter encompasses a wider conceptual range.

Conceptual Characteristics

Goertz (2018) identifies a series of guidelines for conceptual development. Some of these are directly relevant for distinguishing different conceptions of peace as well as identifying their strengths and weaknesses.

The first decision is whether to regard a concept as binary or dichotomous versus existing along a continuum. The former tends to be conceived as a characteristic that is present or not (alive–dead) as opposed to something that can exist as a matter of degree. Thus, peace can be defined as a state of being or as something that can vary between two endpoints. Goertz (2018) notes that if there is a continuum, and this is the preferred option, scholars should pay close attention to theorizing the middle portions of that range (what he calls the “gray zone”); the extreme points might be clear, but the partial values of the concept deserve close attention as well.

Somewhat related to the previous issue is whether the concept in question is the product of a single attribute or is multidimensional. Thus, is peace defined by one factor, or are there several elements that make up its conceptual core? If peace has multiple components, then one concern is the relative weighting or relative importance of those attributes (both conceptually and ultimately operationally) in their aggregation to form a single concept.

A third conceptual characteristic with direct relevance for peace is the scope of the conceptual definition: the range of cases or subjects to which the concept is said to apply. With respect to peace, there might be considerable variation. Some concepts purport to apply to both interstate and intra-state relationships, whereas others are confined to one or the other. Others are drawn more narrowly. For example, the so-called “Long Peace” after World War II is defined as the longest period of history without a war, but only between major power states (Gaddis, 1987). Some positive peace definitions deal only with post-conflict (that is, after civil war) states, and then only with internal conditions.

Finally (at least for the present purposes here) is the idea of concept symmetry and its implications for theorizing and causal inference. “Conceptual symmetry means that the opposite or negative pole is the mirror image or inverse of the positive pole” (Goertz, 2018). This can be common when there is a binary concept such as peace being juxtaposed with war. Conceptual asymmetry has some downstream consequences, as Goertz argues that it naturally leads to causal symmetry. This is illustrated by Blainey’s classic work The Causes of War: “War and peace appear to share the same framework of causes . . . The same set of factors should appear in explanations of the outbreak of war [and the] outbreak of peace” (1973, p. 293). Nevertheless, this is often assumed, and peace concepts that fall prey to this might be incorrect theoretically and empirically.

Negative Peace

Negative peace is the concept on which there is most agreement, defined by the absence of war or large-scale violence, depending on the level of analysis. It is also a necessary, but not sufficient, component of most positive peace conceptions, which take the absence of war as a starting point. It has most often been applied to interstate conflict, but it can have a broad scope to encompass intra-state conflict as well. Regan (2014) traces some of the origins of scholarly notions of negative peace to the work of Wright (1954) and Cottrell (1954). There the distinction was made between what can be called “negative peace” and “positive peace.” This differentiation, and in particular an illumination of the latter, would later become identified with the classic work of Galtung (1969).

Negative peace is often paired with different adjectives, but with similar conceptual underpinnings. These include “precarious peace” (George, 2000), “adversarial peace” (Bengtsson, 2000), “pre-peace”(Bayer, 2010), “conditional peace” (George, 2000), and “cold peace” (Miller, 2001). These are defined by the absence of full-scale war, usually in reference to interstate relations. Nevertheless, there is the expectation that significant hostility and risk of war exist between states in these conceptions; thus, their scope might be limited to what have been called rivalries (Colaresi, Rasler, & Thompson, 2008) in periods without war. Other efforts broaden negative peace to include cyberwarfare (Hampson, 2017) and sexualized violence (Enloe, 2017).

Still, within the genre of negative peace, additional formulations incorporate other adjectives, including words such as “stable” or “unstable” (Goertz, 2005). Related to this is the concept of “sustainable peace” (Deutsch & Coleman, 2012), a priority of the United Nations (UN, 2018). We do note, however, that the UN generally moves beyond negative peace when using the term “sustainable peace,” but these other elements (e.g., economic development) are treated as independent variables leading to peace, rather than part of the concept itself. The use of such additional language not only potentially limits the scope of the peace concept but also threatens the core element. “Stable” and “sustainable” confound two separate issues: the duration of a state of affairs with the level of peace or hostility. All kinds of peace (and indeed hostility as well) can be stable or sustainable. Peace should not imply an enduring quality or resistance to change; these are aspirational elements, not conceptual ones. Such modifications raise important theoretical and empirical questions but are not those that scholars should use to construct the central concept of peace.

A problem with the binary and modal negative peace conception is that it produces a heterogeneous set of cases (Goertz, 2018) in the peace category, whose only common characteristic is the absence of war or large-scale violence. In the peace-as-not-war conception, India has been at peace with Pakistan for most of the six-plus decades, save for four short wars. The same is true for the U.S.–Soviet Union relationship during the entirety of the Cold War, a period without direct war between the two superpowers. That these relationships are just as “peaceful” as contemporary French–German relations lacks face validity. Similarly, with respect to internal peace the problems are equally acute. The end of civil wars when one side achieves victory—as happened in Rwanda—is peaceful only in a negative sense. Nevertheless, given the continuing violence there (albeit at lower levels than that of genocide) and human rights violations, it seems incongruous to classify that state in the same category as Belgium, which has its own struggles with ethnic-linguistic differences.

There are some exceptions to negative peace conceptions that rely on a single attribute. The Global Peace Index, or GPI (Institute for Peace & Economics, 2018), ranks all countries of the world based on a number of objective indicators; this is a country-level measure but includes primarily internal elements as well as some on relations with other states. The GPI is a composite index of 23 indicators across three dimensions (ongoing domestic and international conflict, societal safety and security, and militarization) weighted and combined into one overall score. Virtually all the indicators are related to negative peace, dealing with violence even as they move beyond the high threshold event of war. This and related approaches fit with the idea that peace is multidimensional and can vary across a given range, producing something approximating a continuum by inductively dividing states according to quintiles in the distribution of scores. This approach is also desirable in that it has clear indicators that can be measured across different political units. Nevertheless, it might be criticized as focusing too much on Western-oriented notions of security.

The GPI is superior to other conceptions in that it has some of the more desirable qualities of concepts noted by Goertz (2018): multidimensional, not binary, and capable of observation. Nevertheless, there are some limitations. There is a mixture of societal characteristics (e.g., perceived criminality) and external elements (e.g., external conflict), with the former given more weight (60%) in the final score, although some are ambiguous as to whether they are internal, external, or both (e.g., military expenditures). It is not clear how appropriate it is to aggregate peace across particular levels of analysis. A state might be very peaceful in the ways that it treats its own citizens, but very hostile toward other states. A related problem with this unitary formulation is that it lacks a relational component. Peace for a state is relative to another actor, and a unitary indicator will disguise very peaceful relations for a state with one actor (e.g., Israel and the United States) and very hostile ones with others (e.g., Israel and Iran).

Negative peace approaches dominate scholarly definitions of the concept and indeed are reflective of most popular references to peace in government statements and media reports; as an example of the latter, so-called “peace agreements” are designated as such when they stop violence in the form of a ceasefire, rather than afterward produce cooperation (if they even do so) between former disputants. Despite these limitations noted, the achievement of negative peace is treated as a prerequisite for more positive peace conditions.

Positive Peace

The concept of positive peace is much more complex than negative peace treatments given that its attributes are multidimensional, but also more diverse in scholarly formulations. Internal conditions receive greater attention than in negative peace, although many conceptual specifications are designed for both. Positive peace also includes more normative values to be maximized or a negative condition that is eliminated from interactions (Galtung, 1981), even as any concept with it carries with it normative content (Goertz, 2018).

Johan Galtung (1971) is perhaps most identified with the positive peace concept, although he was not the first person to use that term. Positive peace in his definition is the removal of structural violence from relationships. Structural violence is envisioned as involving inequality in the distribution of power and the prevailing culture. This includes eliminating political repression, poverty and hunger, limited access to healthcare, and a series of other problems that diminish human lives. Clearly, this is a different and much broader definition of violence than other formulations. Others have followed this lead and defined positive peace as the absence of fundamental conflicts, even those that do not involve the use of force (Young, 2010).

As a starting point and as influential as it has been, there are several problems with this conceptualization. First, it is similar to negative peace in terms of defining something as its inverse; here more than war is lacking. Second, it is so sweeping as to encompass almost everything that affects human lives, and it is unclear what the ideal (utopian?) and other extreme point might look like, even as a continuum can be envisioned. This makes the definition of limited utility for empirical research on peace, given the resulting difficulties in operationalizing the concept. In its favor, however, Galtung’s has the potential to apply to a wide range of actor relationships, from individual to groups, to those within and between countries. Some argue, however, that structural violence can only be understood and evaluated in specific cultural contexts, as peaceful societies “may not share the researchers’ implicit values about equality, basic needs, physical reality or spiritual reality” (Smoker, 1981, p. 153). This framework shares some similarities with some critical theory formulations that also incorporate concerns with gender, resistance, and the environment (Richmond, 2017).

Two other prominent figures have developed positive peace approaches that have influenced scholarly research. Immanuel Kant’s “perpetual peace” (Kant, 1795) is focused on interstate relations, and his conception includes negative peace elements such as the elimination of standing armies, non-interference in the affairs of other states, and avoidance of concerns that might prompt war or violence between states. Its positive peace tradition elements call for republican forms of government in every state and the rule of international law governing international relations. This conception is the underpinning of “liberal peace,” which has become the foundation for many peacebuilding efforts in post-conflict contexts, as well as the research on the “democratic peace” (see Russett & Oneal, 2001, for work on the “Kantian Triad”).

John Paul Lederach, one of the giants in the field of peace studies, defines “justpeace” as “(1) an adaptive process-structure of human relationships characterized by high justice and low violence, (2) an infrastructure of organization or governance that responds to human conflict through nonviolent means as first and last resorts, and (3) a view of systems as responsive to the permanency and interdependence of relationships and change” (Lederach, n.d.). The conception is highly abstract, but other scholars have understandings close to these ideas. For example, the second point is consistent with Chenoweth (2017) and Crocker (2017), who indicate that conflict between actors at any level can be expected (even inevitable), but it is how that conflict is managed that matters; peaceful societies and interactions manage or resolve conflicts through non-violent means.

At the group or community level, there are formulations that define the characteristics of peaceful intergroup relations, often derived from anthropological studies. Fry (2006) identifies eight different factors: (a) overarching social identity, (b) interconnections among subgroups, (c) cooperative forms of interdependence, (d) non-warring values and taboos against violence, (e) symbols and ceremonies celebrating peace, (f) institutions that support integration, (g) conflict management mechanisms, and (h) visionary leadership. It is not clear whether these are mutually exclusive, how they might be related to one another, and how they might be weighted in importance or causal sequence.

All of the previous approaches are what might be referred to as “top-down” approaches, in which scholars take states or state relationships as the units of analysis. In contrast, the Everyday Peace Indicators Project (2017) adopts a “bottom-up” approach that asks local people to reflect on the conditions of peace. This approach is largely “inductive, localized, interested in granularity, and possibly community sourced” (Firchow & MacGinty, 2017). This produce a series of narratives about what peace means to individuals, and the resulting narratives lead to different understandings of peace than top-down treatments (MacGinty & Firchow, 2016; see also Firchow, 2018). Although this project is designed to produce operational indicators of peace (e.g., it is safe to walk the streets), the indicators reveal conceptual underpinnings. The project directors are able to classify the indicators into 16 different categories that include both negative (e.g., crime, personal security) and positive (e.g., education, access to healthcare) elements (Firchow & MacGinty, 2017).

The Global Peace Index also has a “Positive Peace Index” (PPI) that is constructed according to eight dimensions or “pillars” (e.g., corruption, flow of information, human capital) that encompass 24 indicators (e.g., economic inequality, judicial independence, scientific publications) (Institute for Peace & Economics, 2018). Although these scores are positively correlated with the GPI scores that are negative peace–based, PPI better taps broader conceptions of peace that deal with issues of economic development, justice, and human rights. Only one of the eight pillars (i.e., good relations with neighbors), however, directly deals with external peace. The definition used in constructing this index confuses conceptual definition and cause: “the attitudes, institutions, and structures that create and sustain peaceful societies” (Institute for Peace & Economics, 2018, p. 62). Some of the advantages and disadvantages of approach that were present with its negative peace cousin are evident here as well.

Two attempts at defining peace deserve special attention for their explicit attempts at conceptualization as well as their ability to meet the stated guidelines for concepts. These are the “peace scale” and “quality peace.”

Peace Scale

Goertz et al. (2016) developed a “peace scale” of five ideal-type categories along which state–state (government) relationships vary; they then aggregate, additive and unweighted, the individual relationships to obtain an international system level conception of peace. The scale was intended ultimately for use in empirical analysis, but the authors devote an extensive discussion to each category before coding actual relationships. The five levels are designed to reflect a continuum and include elements of both negative and positive peace. Six considerations help define the ideal category types: (a) the presence or absence of war plans; (b) the frequency and severity of conflict, especially militarized; (c) the salience of issues in dispute and whether they are mitigated or resolved; (d) the existence and institutionalization of communication channels; (e) the state of diplomatic relations and coordination; and (f) the degree to which interstate cooperation between the pair exists and is institutionalized.

On the hostile side of the continuum are severe and lesser rivalries that are characterized by militarized conflicts and threats. Cases within two types of competitions could appear on different sides of the dichotomy of war/no war. Rivalry relationships can exist without wars (e.g., U.S.–Soviet Union) and even when they do occur, it is infrequent relative to non-war periods (e.g., India–Pakistan). Thus, on the peace scale, cases in these categories depend on ongoing hostile relationships and not events. Therefore, these tend to be stable regardless of periods of war, whereas in traditional negative peace formulations they would oscillate between war and peace according to whether the former was occurring or not.

The middle position, or the center of the gray zone, is designated as negative peace, but that label means something different from traditional conceptions as it extends beyond the absence of war. States in negative peace here are neither close friends nor enemies. A wide range of relationships are found in this category, from former rivals (e.g., Israel–Egypt) to those states that have a number of disagreements, but some positive interactions as well (e.g., China–Australia). The peaceful side of the continuum gets at different types of positive peace. These involve expectations and mechanisms for peaceful conflict resolution, and that war or the use of military force as a means of conflict resolution is “unthinkable” or has a zero probability. Characteristic of these relationships are (a) absence of major territorial claims, (b) institutions for conflict management, (c) high levels of functional interdependence, and (d) satisfaction with the status quo.

The categories on the positive peace side of the scale are warm peace (e.g., United States–Israel) and security communities (e.g., European Union members). The concept of security communities was initially developed by Deutsch, Burrell, and Kann (1957) (see also Adler & Barnett, 1988). This is not formal merger of two political entities, but rather states retain their sovereign independence to a substantial degree. War is not only unthinkable between members, but also the parties are tied together by extensive communication links and transaction flows (Deutsch et al., 1957). Security communities might also involve shared identities, values, and meanings, as well as interactions at several levels (e.g., private as well as governmental) and common long-term interests (Adler & Barnett, 1988). The relationships are mutually rewarding and reflective of harmonious interests (Alker, 1977). Warm peace states are different from security communities more in degree than kind, with less integration and harmonization of policies.

Quality Peace

Several works from scholars with various connections to the Kroc Institute at the University of Notre Dame have added the word “quality” as an adjective to “peace,” largely to indicate a difference with the standard negative peace orientation. The scope of quality peace derives from the theoretical and causal interests of the researchers, largely confined to civil contexts, and then even more narrowly to post-conflict societies (Joshi & Wallensteen, 2018a; Wallensteen, 2015). Nevertheless, there are extensions that aspire to expand the context to all forms of relationships (Davenport et al., 2018).

The initial foray into quality peace (Wallensteen, 2015) was focused on post-conflict contexts, specifically after civil wars. In this way, the research was designed to contribute to understanding the conditions for successful peacebuilding. First, however, the end game needed to be specified, and that is where defining the peace concept comes in. Initially, Wallensteen (2015) identified three dimension of quality peace, all designed to reduce the recurrence of violence but involving much more than purely negative peace. Predictability refers to establishing conditions that are unlikely to be reversed, akin to stability. Economic development concerns can be part of this dimension. Dignity refers to establishing equal rights for opponents, and eliminating discrimination, repression, and related acts. Depending on the context, reconciliation, acknowledging guilt, and justice for war crimes victims might also come into play. Security encompasses the rule of law, gender equality, and eliminating corruption among others.

A subsequent study refines that definition and contributing authors explore the different elements in various post-conflict settings (Joshi & Wallensteen, 2018a, 2018b). Each of these dimensions is treated as a necessary condition for quality peace. Security is still a definitional element, but here it deals more with demilitarization and lessening the incentives for violence; this is in keeping with the idea that negative peace is an element of positive peace, but not the only one. Security for all (including gender equality) remains a part of this dimension. Thereafter, there are four dimensions, consistent with the previous quality peace formulation but much more precise. Economic Reconstruction gets its own element, and investment growth, job creation, and a stable economy are the sub-elements. Reconciliation/Transnational Justice receives heightened attention; this dimension is part of peace that is unique to a post-conflict context. Two other dimensions drawn from the peacebuilding literature get their own dimensions and extend the earlier formulation: Good Governance and Civil Society.

Quality peace was initially borne to apply to the post–civil war context, even as the authors make reference to it as applicable in some ways to broader contexts and levels above and below the state. Nevertheless, another project, with three authors providing individual concepts of quality peace, takes on the ambitious task of creating quality peace conceptualizations that transcend levels; that is, they are designed to apply to subnational, state, and interstate relationships (Davenport et al., 2018).

Regan’s perceptual formulation is closest to negative peace: “No actor or group has a unilateral incentive to attempt change by force of arms” (2018, p. 86). He focuses on the incentives or preferences of actors rather than capabilities. Quality peace occurs when the status quo is favored by all. Melander (2018) labels his version of quality peace as “procedural,” and it has three elements beyond the absence of war: (a) respect for physical integrity rights, (b) democratic political institutions, and (c) equality—in particular gender equality.

The most expansive and detailed attempt at quality peace is the Davenport (2018) Peace Scale. His seven-point scale also incorporates categories describing the full range of relationships, not merely peaceful ones. The seven categories include three on the hostile side of the scale (“Opposition,” “Overt Aggression,” and “Latent Aggression”) and three on the peaceful side (“Latent Cooperation,” “Overt Cooperation,” and “Mutuality”). Hostile and peaceful relationships are separated on the scale by the middle category of “Indifference.” Four dimensions determine the placement of relationships in the seven categories: behavior, organization, language, and values. For example, the highest form of peace—Mutuality—involves integrating and consistent behaviors, inclusive organizations, language that refers to shared identities and common missions, and shared and positive values of community.

Conceptions of Peace in Scholarly Practice

The previously cited works generally made explicit attempts at conceptualizing and/or measuring peace. International studies scholarship, however, has reflected different definitions of peace, even as little or no attention might be devoted to it in the writings. In “Theory,” “Empirical Studies,” and “Teaching,” consideration is given to how peace conceptions are evident in grand theory, empirical studies of war and peace (including peacekeeping and peacebuilding), and in international studies pedagogy.


Grand theory in international relations has primarily been concerned with war between states and the conditions associated with its onset or prevention. In doing, so, the major theories de facto make claims about what it means for states to be at peace (see Richmond, 2008; Diehl & Goertz, 2018, for a more extensive review). Perhaps not surprisingly, because of the focus on war, peace is normally framed as negative peace or the absence of war. Attention is primarily devoted to state–state relations.

Realism is almost exclusively concerned with negative peace (Morgenthau, 1948). Classical realism assumes a state of anarchy in the world. At best, an international system of self-help might produce some cooperative arrangements, such as arms control agreements (Glaser, 19941995), but these tend to reinforce negative peace rather than promote deeper forms of cooperation such as integration. “Victor’s peace” is established by victory of one side or state in a war but does not necessarily involve the values of justice, equity, or other components of the positive peace variety; it is a reflection of the self-interest of the hegemon (Richmond, 2008). Its pessimistic view of human nature and international anarchy imply that positive peace is unattainable or at best fleeting.

The focus of liberalism is still on negative peace, but there is room for greater cooperation and potentially positive peace as well (Moravcsik, 1997). Liberalism recognizes that under some conditions (generally when powerful domestic political and economic interests are served), negative peace is more likely, and potentially positive peace in the form harmonized policies, coordinated actions, and even economic integration of various types (e.g., common currency) (Keohane, 1984). The so-called “liberal order” is largely a system-level phenomenon (see also Wallensteen, 1984, on system level peace). Perhaps the most prominent variant of liberal theory is democratic peace theory—democratic states don’t fight each other. Trade and international organizations are facilitating conditions, and not necessarily the consequences or conceptual components of more peaceful relationships, and therefore the focus is on negative peace (Russett & Oneal, 2001).

Constructivist theories, even as they emphasize international norms, are still concentrated in negative rather than positive peace. Representative of this is the seminal work of Wendt (1999). His three systemic “cultures” illustrate different forms of peace, generally at the system level but having implications for state–state relationships. States in the Hobbesian culture don’t recognize the right of others to exist and view violence as a legitimate means to achieve ends. This leads to endemic and perpetual war, and therefore even negative peace achieved through states balancing one another is fleeting. The Lockean culture is based on rivalry, and violence is still prevalent, albeit with some limits, including respect for sovereignty. Again, the underlying logic envisions largely negative peace. The Kantian culture is the third variant and is based on friendship. In this culture, the main norms are peaceful resolutions of dispute (anti-violence) and mutual aid in the event of third-party threat. The structures and underlying norms are consistent with the concept of pluralistic security communities (Deutsch, Burrell, & Kann, 1957). Still, the focus is primarily on traditional security matters even as war is “unthinkable.” Other aspects of positive peace, including economic integration, human rights, and justice, are not part of this approach.

Marxist theory is perhaps the closest alterative framework for positive peace concerns, in that it emphasizes economic justice, albeit of a particular variety (Brewer, 2002). Negative peace is still a part of the formulations, but equitable sharing of resources (a positive peace vision) is a characteristic of a socialist and peaceful state. Various other theoretical approaches—such as critical theory, postcolonialism, and some variants of feminist theory—raise positive peace concerns such as social justice, egalitarianism, and economic development. The focus there, however, is largely to critique existing theories such as liberalism for ignoring these concerns or to criticize existing international orders for denigrating them. The elements of positive peace (although the term is infrequently used) are largely determined by the particular values espoused by the authors.

Overall, international relations theory is wedded to negative conceptions of peace. To the extent that positive peace is considered, it comes more from normative prescriptions rather than from parts of the theory that can account for positive peace outcomes.

Empirical Studies

War has arguably been the most studied phenomenon in international studies scholarship. What do those studies reveal about conceptions of peace, and what about studies that purport to study peace directly? Most studies historically dealt with interstate peace, although studies of civil conflict became increasingly common over time. Despite some increase in breadth, studies—especially those using quantitative approaches—have sought to keep normative concerns and preferences separate from empirical concerns.

The idea of peace as the absence of war is by far the most common one in scholarly discourse. This is consistent with the large majority of war studies that look only at violence and make little or no reference to peace research on human security and other elements of positive peace; consideration of the democratic peace and the liberal peace are perhaps the only connectors between those literatures (Bright & Gledhill, 2018).

Two studies conducted a systematic examination of articles in major journals and professional conferences with respect to how they conceptualized peace. Gleditsch, Nordkavelle, and Strand (2014, p. 155) examined articles published in the Journal of Peace Research and Journal of Conflict Resolution, concluding: “Negative peace, in the sense of reducing war, has always been the main focus of peace research.” Similarly, using a different coding scheme, Diehl (2016) reports similar findings using their replication data. He also finds that papers presented at an annual meeting of the International Studies Association, arguably a place where positive peace concerns should receive greater attention, are more heavily weighted on negative peace than positive peace concerns. Those that mention “peace” and fit in the positive peace category cast a wide net of what is contained in the category, including conflict resolution, human rights, reconciliation, justice, economic development, human security, and gender. Generally, such studies examine only one aspect of positive peace rather than offering a multidimensional definition.

Although scholarly research on war implicitly assumes a negative peace conceptualization, what about work that explicitly deals with peace? Two relevant and related literatures are those concerning peacekeeping and peacebuilding, the latter of which is focused on internal peace. In both milieus, peace is the dependent variable, and by examining the desired outcomes and indicators of success, one can gain insights into what underlying concepts are involved.

For studies of traditional peacekeeping and its ability to supervise ceasefires, negative peace is the clear focus of most studies, whether the focus is on internal or interstate peace. There, “peace duration” (time until violence renewal) and “deaths from violence” are the measures that are consistent with a negative peace orientation (Diehl, 2014); little consideration is given to other conditions that follow such operations. The advent of peacebuilding operations, however, broadened the outcomes explored, and many fit with positive peace conceptions and are consistent with some of the dimensions of quality peace. Successful peacebuilding varies substantially in studies (Jenkins, 2013). Some emphasize aspects of individual human security, including human rights protection, access to food and medical care, and the like. Others operate at the level of the state and de facto define peace as the achievement of democratization, economic growth and stability, and the rule of law (see Diehl & Druckman, 2010, for evaluation questions and indicators of peacebuilding).


Although scholarly research on peace can have direct and important influences on policymaking, perhaps more broadly significant is how we conceptualize peace when we teach about it. This affects how our students—citizens and some future leaders—think about the subject and which peace values they regard as worthy. For illustrative purposes, I identify three ideal, or what might even be called stereotypical, types for how issues of war and peace are covered in universities. The focus is largely in individual courses, as opposed to a full curriculum, within political science, international relations, or international studies units; this is a reflection of the dominant contexts for courses in these subject matters.

Perhaps the most common approach is what might be labeled as the “war and negative peace” orientation. In these courses, the conditions for war and conflict are examined in detail (see Mitchell & Vasquez, 2013; Quackenbush, 2014, for sample textbooks). These are courses on interstate conflict and/or security studies that are found in most universities around the world. Prominent topics on syllabi and in textbooks include alliances, power distributions, and the like, largely from the realpolitik point of view. With the end of the Cold War, the number of conflict courses has expanded to include those on civil war, terrorism, and political violence more broadly. Nevertheless, the content of such courses still emphasizes the onset or escalation of the particular kind of conflict in question. The only “peace” that is addressed in these courses is of the negative variety: peace is defined as the absence of war. Thus, the absence or diminution of the conditions associated with war and severe conflict is judged to be the desired end goal. Courses under this rubric are essentially about war and cover peace only in the most cursory and narrow fashion. Incidences of state–state cooperation are largely ignored except in the form of alliances that serve to defeat or deter opponents. Cooperation concerns are shunted off to companion courses on international organizations or international political economy. Curriculum on civil wars and the like occasionally deal with societal transformations, but only following civil wars.

The war and negative peace approach has value for understanding the conditions for violent conflict. Indeed, understanding and eliminating or mitigating those aspects might be necessary conditions for deeper features of peace. Nevertheless, by teaching about peace by focusing on what it isn’t rather than what it is, students are short-changed in their potential understanding, and it sets a low aspirational bar for what they should be encouraged to promote. In addition, the focus on conditions or “causes” of war provides misleading inferences about what factors or processes might promote positive peace. For example, alliances might be important for war and negative peace, but largely irrelevant for promoting human security. This is the problem of causal symmetry noted at the outset of this essay.

A second ideal type or approach might be labeled as “conflict management,” courses that focus on the processes that actors use to mitigate the worst elements of disagreements and in some instances resolve differences between them; these are often broadly applicable at multiple levels of analysis. A general course often addresses a variety of approaches, and there can be, especially at the graduate level, individual courses on those topics. Although labeled as promoting peace, some conflict management courses include attention to coercive tools. Deterrence is conceived as an appropriate topic if the goal is to avoid confrontation or escalation. Almost paradoxically, military intervention appears as a conflict management approach. In evaluating these interventions, scholars often make the assumption that the intervening parties’ goal or desired outcome is to stop the fighting. This provides a veneer of peace (albeit one of the negative variety) to these topics but ignores self-interested motives of the interveners. The scholarly literature and associated course content, with some exceptions, ignores the aftermath of the interventions with respect to a variety of peace concerns, such as human rights, development, and justice. To be fair, conflict management courses sometimes make distinctions between humanitarian and non-humanitarian interventions. The former comport better with a positive peace orientation in that they are dedicated to lessening human suffering, and the use of military force is an instrument to promote a greater good. Sanctions as a conflict management tool are also a subject matter for war and peace instruction; again, the topic emphasizes coercion to produce a desired end state rather than cooperation or consent.

Conflict management instruction, reflected most obviously in textbooks (e.g., Bercovitch & Jackson, 2009; Greig, Owsiak, & Diehl, 2019), in other ways comes closer to finding a balance between war and peace concerns. Subjects such as negotiation and mediation involve largely consensual ways for disputants to manage their disagreements. Similarly, legal mechanisms—whether international or national courts or arbitration—are topics that allow students to understand how disagreements can be channeled into non-violent processes and hopefully resolved without the threat or use of force. Peace does not mean that disagreements or disputes won’t arise—indeed, they might be inevitable in the human condition. Rather, conflict management emphasizes that peace means having the appropriate institutions to deal with disagreements when they do arise; the rule of law is one example. Traditional peacekeeping is also covered in many conflict management and resolution courses, with the focus on when it is able to prevent a renewal of warfare.

By definition, conflict management means that there is already conflict (and often war) present, so the starting points are situations in which peace is absent. As with the previous approach, negative peace is often the focus. Peacekeeping is designed to prevent a renewal of violent conflict; mediated conflicts produce primarily ceasefires; and legal outcomes are, at best, fixes to single disagreements that might (or not) promote more peaceful interactions in the future. In these ways, conflict management still privileges the war element and is firmly rooted in a negative peace orientation.

A third approach might be labeled as “peace studies.” Unlike the previous two approaches, such courses are frequently offered outside of conventional disciplinary departments and are part of a separate curriculum of an interdisciplinary unit. Courses explicitly devoted to peace are much less common than those that have “war” or “conflict” in their titles. Peace studies units in universities are generally rare, and even then often marginalized, at institutions of higher education in North America and Europe, and indeed on other continents.

The major difference between peace studies and the previous two approaches, however, lies in its emphasis on “positive peace.” That is, a peace studies course deals with subjects beyond the absence of war and the conditions that de-escalate conflict to those that promote a variety of other values. The concern with positive peace is consistent with a shift in orientation toward human security concerns.

Peace studies courses tend to have a more explicit normative orientation, often combined with a critique of the status quo. The subject matter of peace studies courses varies. The leading textbook (Barash & Webel, 2014) for such courses contains extensive chapters on the causes of war and terrorism as well as on various conflict management approaches such as mediation and international law. In some ways, it covers much of the same ground as the previous two approaches to war and peace, albeit from a different perspective. More reflective of positive peace, that book includes chapters and sections on human rights, the environment, poverty, and other issues that are eschewed by courses focused on negative peace. Increasingly, issues of peacebuilding are the focus of such courses.


Peace is far less developed conceptually, and also in terms of associated research, than war. There are some hopeful signs of change, but peace is still largely conceived as the absence of war, or negative peace. Although perhaps useful for studies of war, this suffers from some of characteristics identified by Goertz (2018) as contrary to good practice in conceptualization: binary, unidimensional, and symmetrical to another concept.

In contrast, notions of positive peace have more desirable qualities, but there is only now an emerging research on this kind of peace, even as it has been the subject of conceptualization for a number of decades. Nevertheless, there is considerably less consensus about positive peace than negative peace components; too often, scholars focus on one or two dimensions, even as collectively we can envision many. Second, positive peace treatments can differ substantially across levels of analysis; peace for interstate relationships cannot be captured by the same conceptual elements as peace within states, within groups, and for individuals. Third, some positive peace concepts muddle the distinction between the definitional aspects of peace and the causal conditions needed to produce peaceful outcomes. For example, are leadership and access to medical care things that define the end state of peace, or are they active agents that lead to the peaceful end state? Despite decades of scholarly discourse about positive peace, it remains an underdeveloped idea.


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