Historically, peace is more frequent than war: most rivalries between human groups – whether organizations, communities, or states – do not result in armed conflict. War or conflicts of all kinds are costly, risky, and potentially destructive. Understanding why war breaks out therefore requires explaining not only why tensions exist – they are almost permanent – but especially why the mechanisms that prevent violence from occurring stop working, making a shift towards war acceptable.
Firstly, the idea of a single cause of war is misleading. Armed conflicts rarely arise from a single event or sudden decision. They more often result from a gradual deterioration of peace, during which a series of institutional, political, and social locks are successively released. War then appears less as a moment of rupture than as the culmination of a path. From this perspective, peace is not the absence of tension; it is an unstable equilibrium.
Secondly, the issue of the justification for war. The actors who wage it always tell a story. In other words, both states and armed groups invoke justificatory narratives – fighting terrorism, national defense, stabilization, or liberation. These narratives are not necessarily deceptive, but they rarely provide a complete explanation for the transition to violence. An analysis of the reasons for conflicts must therefore go beyond the declaratory, to identify the deeper mechanisms that make violence first possible, and then acceptable.
Reading war as a trajectory, rather than an event, thus allows for a better understanding of why it remains a constant possibility in human history.
Three main mechanisms structure this shift from peace to war, progressively making compromise impossible.
The first refers to grievances, i.e., economic or political injustices that fuel collective mobilizations. Armed conflicts more easily emerge when entire groups perceive themselves as perpetually disadvantaged in access to resources, power, or recognition. When these frustrations become collective and lasting, violence can appear as a means to obtain redress or visibility. The Sri Lankan conflict provides an illustration. From the 1950s, several linguistic and administrative policies marginalize the Tamil minority in access to public jobs, higher education, and political representation. This accumulation of inequalities gradually fuels the radicalization of part of the Tamil movement and contributes to the formation of the Liberation Tigers, who will lead an armed insurgency for many years.
The second mechanism concerns the opportunities for war. Frustrations alone are not enough to produce an armed conflict; it is also necessary for the violent option to become materially feasible. Research shows that conflicts are more likely when the costs of opportunity are low – for example, in contexts of poverty or unemployment – and when sources of funding exist. Natural resources, illicit economies, or control of strategic territories can provide armed groups with the means to sustain a lasting mobilization. The civil war in Sierra Leone is an example of this, with the Revolutionary United Front rebels managing to finance their insurrection by controlling alluvial diamond deposits. These resources allow them to buy weapons, recruit fighters, and prolong the war despite the absence of massive popular support.
The third mechanism relates to institutional structures that frame conflict management. Societies normally have institutions – political, judicial, or administrative systems – that allow disputes to be resolved without resorting to violence. When these institutions become weak, biased, or unable to guarantee agreements, rivalries can degenerate into confrontation. The collapse of the Somali state in the early 1990s illustrates this phenomenon. After the fall of Siad Barre’s regime in 1991, clan rivalries turn into armed conflicts in a context where no recognized authority can impose or guarantee a lasting compromise.
At the heart of these dynamics is always the same question: who wins and who pays for war? When some actors can capture the benefits of conflict – political power, control of resources, or economic rents – while externalizing its costs onto the population, escalation becomes more likely. The example of the Falklands War illustrates this point: a junta facing internal challenges and believing that opening a conflict could provide a solution to its situation.
In this perspective, and as demonstrated by Blattman, war occurs when compromise becomes impracticable. This moment generally corresponds to the gradual collapse of the mechanisms that allow adversaries to negotiate rather than fight. The European crisis of 1914 illustrates this mechanism well: after the assassination of Archduke Franz Ferdinand, several mediation attempts fail and military mobilizations succeed each other, gradually reducing the space for compromise.
In addition to economic and institutional factors, war is also rooted in deeply human dynamics. Research from anthropology and evolutionary psychology, particularly Mike Martin’s analysis, highlights the central role of status, belonging, and leadership in collective violent behaviors.
Human societies are structured around hierarchies and prestige dynamics. Leaders can mobilize these dynamics to consolidate their position or strengthen group cohesion against an external enemy. From this perspective, war can appear as a mechanism for consolidating power or restoring collective status.
Group dynamics also play a determining role. Individuals tend to favor their belonging group – a well-documented phenomenon in social psychology. This polarization of “us” and “them” can transform material rivalries into identity conflicts.
Beyond the cited factors, four elements potentially aggravate the situation and facilitate the transition to war.
Strategic uncertainty is a first factor. Actors may misjudge the intentions or capabilities of their adversaries, thinking that it is necessary to go to war or that the other will do so. The Yom Kippur War in 1973 shows how strategic uncertainty can trigger war: Israel underestimates Egyptian and Syrian intentions, misinterprets several warning signals, and is caught off guard by an offensive that its decision-makers deemed unlikely.
Credibility issues of each stakeholder’s commitments also play a central role. If an agreement cannot be guaranteed over time – especially when the balance of power evolves – actors may prefer to fight immediately to avoid a future situation of weakness. The most well-known example here being the Russo-Japanese War of 1904, which illustrates the credibility problem of engagements: Japan fears that Russia will gradually strengthen its position in Manchuria to the point of rendering any future compromise meaningless, prompting Tokyo to prefer immediate war to a negotiation without guarantees.
Perception errors also reinforce these dynamics: overestimation of one’s own strengths, underestimation of the opponent, or spirals of mistrust. In summary, the shift towards war occurs when actors have a poor understanding of their probability of winning (at least one of the two). In this context, deceptive maneuvers aimed at hiding capabilities or intentions complicate strategic reading and can push for the outbreak of conflict.
Finally, immaterial incentives – honor, humiliation, revenge, or sacredness of conflict – can turn a confrontation into an existential conflict. The 1914 crisis illustrates, for example, how national honor can lock diplomatic options: for Vienna as well as for St. Petersburg, retreating would have meant losing face, which contributed to turning a regional crisis into a general war.
Understanding war thus consists less of identifying a single cause than observing the trajectories that lead to the rupture of compromise.
This understanding is not only a matter of historical analysis. It can also contribute to conflict prevention. Identifying warning signs – rising inequalities between groups, lasting political exclusion, weakening institutions, or radicalization of identity narratives – can sometimes allow interventions before the mechanisms of violence become irreversible.
This is precisely the goal of early warning systems developed by many international organizations. These devices seek to detect weak signals of escalation – political tensions, institutional degradation, social polarization, or progressive militarization of rivalries – in order to allow diplomatic or political interventions before conflict erupts.
