Ending a war is relatively simple. You negotiate terms, sign documents, shake hands for cameras. Keeping the peace afterward is where most agreements fail.

Studies of post-Cold War conflicts reveal a sobering pattern: roughly half of all negotiated peace agreements collapse within five years. Civil wars are particularly prone to resumption. The settlements that looked promising on paper become kindling for renewed violence.

Yet some agreements endure. Colombia's 2016 deal with FARC rebels, despite a referendum defeat and ongoing challenges, has largely held. Mozambique's 1992 settlement transformed former enemies into political competitors. What distinguishes these successes from the failures isn't just luck or goodwill—it's a specific combination of institutional design, external support, and careful management of those who profit from continued bloodshed.

Every armed conflict creates winners—not just military victors, but entrepreneurs of violence. Warlords who control smuggling routes. Commanders whose status depends on leading troops. Businesspeople who've captured lucrative contracts in conflict zones. These actors have rational reasons to torpedo any agreement that threatens their position.

Political scientists call them spoilers, and their management determines whether agreements survive their first years. The most dangerous spoilers often sit at the negotiating table itself, signing agreements they have no intention of honoring. Others operate from outside, launching attacks designed to provoke retaliation and restart the cycle.

Successful agreements address spoilers through multiple mechanisms. Power-sharing arrangements can co-opt potential saboteurs by giving them stakes in the new order. Security guarantees can reassure combatants that disarmament won't leave them vulnerable. Economic integration programs can redirect war profiteers toward legitimate business.

The Burundi peace process illustrates both the challenge and potential solutions. Multiple rebel groups and political factions had competing interests. The 2000 Arusha Agreement succeeded partly because it offered extensive power-sharing across ethnic lines and created pathways for combatants to enter the political system or formal military. Not every spoiler was neutralized, but enough were brought inside to prevent collapse.

Takeaway

Peace agreements fail when they ignore the rational interests of those who benefit from war. Sustainable settlements don't just end fighting—they restructure incentives so that former combatants gain more from peace than from renewed conflict.

Signing a peace agreement requires trusting your former enemy to honor their commitments. After years of violence, that trust doesn't exist. This credible commitment problem kills more agreements than any other factor.

Consider the dilemma facing a rebel commander asked to disarm. If the government later reneges on promised political reforms or amnesty provisions, they'll be defenseless. The government faces a mirror image: if rebels retain hidden weapons or cadres, concessions could be exploited. Both sides have rational reasons to cheat, and both know it.

International involvement transforms this dynamic. UN peacekeepers create buffer zones and monitor cantonment sites. International observers verify that troops are actually demobilizing. Economic assistance tied to implementation milestones gives both parties incentives to follow through. External mediators can call out violations before they spiral.

The evidence is striking. Research by political scientist Virginia Page Fortna found that peacekeeping operations reduce the risk of war resumption by 75-85 percent. Agreements with strong international monitoring mechanisms survive at dramatically higher rates than those left to the parties alone. This isn't about imposing solutions—it's about providing the security guarantee that makes mutual disarmament possible.

Takeaway

Trust is the scarcest resource after war. International involvement doesn't impose peace—it provides the external guarantee that allows former enemies to take the risks that peace requires.

Mass atrocities demand accountability. Victims deserve recognition. Impunity encourages future violence. These principles seem unanswerable—until you're trying to convince war criminals to lay down their arms.

This tension between justice and stability haunts every negotiated end to violent conflict. Offer amnesty, and you may secure peace while embedding perpetrators in the new order. Insist on prosecution, and you may prolong fighting as commanders calculate that surrender means prison.

Different contexts have produced different solutions. South Africa's Truth and Reconciliation Commission offered amnesty in exchange for full disclosure—a middle path that prioritized acknowledgment over punishment. The International Criminal Court's involvement in Uganda arguably prolonged the conflict as Lord's Resistance Army leaders feared prosecution. Colombia's transitional justice system created special tribunals offering reduced sentences for truth-telling and victim reparations.

No universal formula exists. But research suggests several patterns. Early, credible commitments about justice mechanisms reduce uncertainty. Involving victims in designing transitional justice increases legitimacy. Sequencing matters—immediate prosecution may be destabilizing, but indefinite delay breeds cynicism. The most durable solutions typically combine some accountability with broader social reconstruction, acknowledging that legal justice is only one component of genuine reconciliation.

Takeaway

Justice and peace aren't always compatible in the short term. The societies that navigate this tension most successfully find ways to acknowledge harm and create accountability without making peace impossible to achieve.

Peace agreements aren't just documents—they're complex institutional systems that must survive hostile environments. The factors that determine success are increasingly well understood: manage spoilers, secure external support, navigate justice carefully.

This knowledge hasn't made peacemaking easy. Each conflict presents unique configurations of actors, grievances, and interests. But it has made failure less inevitable. We now know that settlements can be designed to improve their survival odds.

The implications extend beyond conflict zones. Any complex agreement—between nations, organizations, or communities—faces similar challenges of commitment, enforcement, and competing interests. The lessons from war and peace illuminate the architecture of durable cooperation everywhere.