Examining why parties in conflict cease fighting

The path to peace usually leads through a ceasefire. In an international project, ETH Zurich researchers have shown the conditions under which parties to civil wars are willing to stop fighting—and why they decide to do so.

Ceasefires are agreements by which one or more parties to a conflict agree to stop hostilities. Although they usually do not solve the problems underlying a conflict, they are always an important step towards ending civil wars.

But why do parties to a conflict decide to lay down their arms in the first place? And when are they more likely to do so? To answer these questions, researchers from ETH Zurich, the Peace Research Institute Oslo (PRIO) in Norway and Uppsala University in Sweden have created the first comprehensive dataset on ceasefires in all civil wars between 1989 and 2020. They examined 2,202 agreements concluded during 109 civil conflicts across 66 countries.

Their study, one of four published in the Journal of Conflict Resolution, shows that the reasons for ceasefires in civil wars are more multifaceted than previously thought and that there are a number of conditions that favor them. The authors focus on intra-, rather than inter-state wars, as the later were the exception during the period under review.

A global phenomenon

In almost all the civil wars between 1989 and 2020, the parties decided at some point to stop fighting, even if just for a limited time. The five countries with the most ceasefires were Sudan (169) followed by India (167), the Philippines (157), Syria (140) and Israel (103).

Most of the ceasefires between 1989 and the early 1990s occurred in Latin America, largely as a result of the peace processes in El Salvador, Guatemala and Nicaragua. Then, from the mid-1990s, most of the agreements were concluded in Europe in connection with the conflicts in the former Yugoslavia. As a result of the conflict in Ukraine, the number of ceasefires in Europe increased again from 2014 on.

In Africa and Asia, ceasefires occurred relatively consistently throughout the period covered by the dataset. In the Middle East, by contrast, agreements were relatively rare from 1990 until the early 2000s. Their numbers increased starting in 2014 due to the Gaza War between Hamas and Israel.

When ceasefires come about

The international research team’s study shows that parties to a conflict are more likely to agree to a ceasefire in periods where the conflict is particularly bloody and when an above-average number of civilians have been accidentally killed by rebel attacks. In South Sudan, for example, the warring factions signed an agreement in June 2018 after the weeks leading up to it were among the bloodiest in the last 12 months.

In addition, the researchers observed that ceasefires are often concluded in the first month of a conflict, as the parties seem to be testing whether or not they are really committed to the war, and if there is a chance for a peaceful settlement after all. If these “early” ceasefire do not succeed, it takes an average of four years for the chances of one to increase again.

The research team also shows that voting out or overthrowing the government during a civil war increases the likelihood of a ceasefire. “The election of a new head of government shows that the people are dissatisfied with the current political situation. That makes it more feasible for a new person at the top to reach out to opponents,” says Govinda Clayton, a researcher at the Center for Security Studies (CSS) at ETH Zurich and one of the leaders of the research project.

For example, Gustavo Petro, the new president of Colombia, announced his intention to negotiate a ceasefire with all armed groups after taking office in August 2022. However, this new-leader effect diminishes after a year, since by then the initial momentum has usually fizzled out.

Political context and international support

The researchers’ analysis also shows that parties to a conflict are more willing to lay down their arms if they have a political justification for doing so. This may be a proposal from a mediating party asking for a ceasefire, or during religious holidays that allow the conflicting parties to stop fighting for a short time without losing face.

In El Salvador, the Farabundo Martí National Liberation Front explicitly justified its willingness to lay down arms by calling it a concession to the mediator, the UN Secretary-General. And in the Afghan civil war from 1989 onwards, temporary ceasefires repeatedly occurred on the occasion of the breaking of the fast following Ramadan.

Willingness to continue combat operations can also be influenced by support from external actors. “Additional troops, weapons or economic aid allow the state to sustain costly conflicts for extended periods of time,” explains ETH researcher Clayton. Following this logic, the researchers from Zurich, Oslo and Uppsala find that ceasefires are less likely during periods when the state is supported by external actors in its fight against rebel groups.

A signal for peace

Although almost all the 2,202 ceasefires aim to stop violence, the reasons behind them vary considerably. One of their most important functions is to promote the peaceful resolution of a conflict. In nearly 70 percent of all the agreements in the research team’s dataset the conflict parties cited this as a primary motivation.

In Colombia, for example, a successful ceasefire agreement was an important part of the process that led to the Revolutionary Armed Forces of Colombia (FARC) rebel group laying down its arms and ultimately to ending the war. And in Sudan, a local ceasefire in the Nuba Mountains proved a key starting point in the process that ultimately produced a comprehensive peace agreement.

In their willingness to forgo violence, parties to a conflict signal their peaceful intentions, build trust and show that they are capable of controlling their own forces. Clayton and his co‑author Corinne Bara of Uppsala University demonstrate that states that conclude and honor ceasefires with a rebel group, for example, strengthen their reputation as a reliable cooperative partner, increasing the likelihood of agreements with other parties to the conflict. At the same time, however, there is a risk that the failure of a ceasefire could destroy the fragile trust between conflict parties and thus jeopardize ongoing peace negotiations.

Military breathers and humanitarian ceasefires

Previous research has focused on the peacemaking function of ceasefires, but Clayton and his co-authors have identified three other reasons why conflicting parties stop fighting.

Ceasefires are often used to achieve political or military objectives that are incompatible with a peaceful resolution of the conflict. “Parties to a conflict use these pauses for instance to rearm or consolidate territorial control over an area,” Clayton says.

One-fifth of all agreements coded in the new dataset, however, are short-term agreements reached for humanitarian reasons, such as the delivery of relief supplies or the recovery of dead bodies from the battlefield. In Syria, local ceasefires gave the besieged population a temporary respite in some places, though the researchers note that these arrangements may also have served broader military strategic goals for the regime.

Ceasefires are also used as a way to manage the conflict. “In these cases, the goal is to contain the devastating effects of violence without moving the parties closer to a peace settlement,” Clayton says. Until Russia’s invasion in February 2022, the 2015 Minsk Agreement between Russia and Ukraine for instance served to contain the violence without ending it altogether.