Historically, peace has mainly been studied from the angle of its treaties. During the 1950s, peace studies reinterpreted the definition of peace and violence: no longer was peace considered simply as the absence of conflict. The social and economic inequalities endangering a more comprehensive form of peace are also denounced.

Historically, the study of peace has focused mainly on peace treaties, like the Peace of Westphalia treaties (1648) that ended the Thirty Years War and established the international system based on the coexistence of sovereign states, the Congress of Vienna (1814) that ushered in the Concert of Nations, and the Treaty of Versailles (1919) ratified between France and Germany after the First World War. It was not until the 1950s that peace studies emerged as an independent discipline, reinterpreting the definition of peace and violence and inspiring a range of intervention tools that are still in use today.

Peace studies

Montesquieu observed how the mechanisms of commerce advance peace in The Spirit of the Laws (1748), while Kant, in his essay Perpetual Peace: A Philosophical Sketch (1795), outlined the various conditions necessary to achieve perpetual peace between republics, based on universal reason and the institutionalization of interactions between states. These ideas were subsequently reworked, notably in theories of democratic (or liberal) peace – highlighting the fact that peace studies can draw upon a long history of philosophical and religious thought on this subject. Nonetheless, academic research has focused above all on seeking to understand conflict.

Inspired by the normative ambition of advancing peace, initial studies of peace undertaken in the United States and Europe during the 1950s started out by undertaking a systematic analysis of war. Working at the intersection of several different disciplines, these researchers adopted a positivist, scientific approach motivated by a concern to legitimize their research with the realist school that held sway in international relations, for whom they were linked with the idealism of the inter-war period.

The creation of the International Peace Research Institute of Oslo (PRIO, 1959), the Journal of Peace Research (1964) and then the Stockholm International Peace Research Institute (SIPRI, 1966) represented landmarks in the institutionalization of this research field. Often linked, sometimes controversially, with pacifist and nonviolence movements, the discipline has since expanded substantially in both methodology and thematic reach, blurring the boundaries with other research fields such as critical security studies. The work of Johan Galtung and the development of concepts of positive peace and structural violence remain its most notable contributions.

Positive peace and structural violence

In his editorial for the first of the Journal of Peace Research, Galtung outlined the binary aspect of the peace concept: negative peace, i.e. “the absence of violence, absence of war”, and positive peace, meaning “the integration of human society.” This definition of positive peace evolved in parallel with the reconceptualization of violence. In response to Marxist critiques expressed during the Vietnam War, favoring a more radical and grounded field of study, Galtung reformulated the foundations of peace research by starting with violence (physical and psychological). He distinguished personal violence (intentional or unintentional) from structural (or indirect) violence, manifest or latent. Intrinsically linked with social injustice, structural violence is “built into the structure and shows up as unequal power and consequently as unequal life chances.” This paved the way for a new definition of positive peace in terms of social justice. From this perspective, social policies around education and healthcare are just as important as military policies – indeed even more so – with respect to achieving peace.

Military and Education expenditure, 2012-2016

Source: World Bank,

Comment: This cloud of dots compares public spending on education (along the horizontal axis) with expenditure on the military (along the vertical axis), both amounts being expressed as share of GDP. Data are only available for a hundred or so states – which excludes China, Nigeria, and Egypt, for example – and it appears that, overall, spending on education is around double that for the army. Some countries spend more on the military sector than on education (Azerbaijan, Pakistan, Russia, Jordan, etc.) whereas, at the other end of the scale, the Scandinavian countries pay at least five times more for education than for the army.

What matters, then, is no longer to regard peace as merely the absence of conflict, but to condemn social and economic inequalities that jeopardize a more comprehensive form of peace, as well as security-focused rhetoric that seeks scapegoats (migrants, the unemployed, marginalized minorities, etc.) rather than analyzing the structural causes of violence. The realization that different forms of inequality anddiscrimination are interdependent, articulated in the concept of intersectionality, complements this analysis by highlighting the plurality of structures of domination and the cumulative impacts of inequalities relating to gender, class, race, age, disability and sexual orientation.

No systematic correlation between migration, unemployment and crime, 2017

Sources: United Nations, Population Division,; World Bank,; Institute for Health Metrics and Evaluation (IHME), Global Burden of Disease Study 2016 Results,

Sustaining peace

In 1976, Galtung proposed three methods for maintaining peace: the dissociative approach (peacekeeping), the resolution approach (peacemaking) and the associative approach (peacebuilding). These concepts were taken up by the UN and still underpin contemporary intervention policies. Peace is often at the heart of the interventionist discourse, which focuses on democratic peace in particular. Building on the empirical evidence that liberal states do not engage in war between themselves, Michael Doyle identifies three pillars – economic, institutional, and ideological – that explain the peace between liberal democracies. Liberal peace theories, which have since been criticized, remain key instruments for justifying some international interventions.

If the definition of peace itself remains contested, the interdependency of security, human rights, economic development and social justice is an established fact. At a time when peace negotiations persist in excluding a large number of stakeholders, women in particular, an inclusive approach to peace seems more consistent with the goal of “sustaining peace” affirmed by the UN alongside its 2030 Agenda for sustainable development.

Female participation in peace negotiations, 1992-2011

Source: UN Women, Women’s Participation in Peace Negotiations: Connections between Presence and Influence, 2012,

Comment: In 2012, UN Women published a report (Women’s Participation in Peace Negotiations: Connections between Presence and Influence) which used a sample of 31 peace negotiations to assess the proportion of women who participate in these processes. This was very low until the late 2000s (around 10% of the negotiators, signatories, and witnesses) and before 2008 there were no women among the head mediators. Negotiations held at the end of this period (2008-2011) show an improvement, with the proportion of women varying from 20 to 30% depending on particular cases and functions.

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