In launching the End of War Project, Laurie Blank and Daphné Richemond-Barak acknowledge that asking the law to end war “may simply be more than it can take.”
Usually, in my view, it is. But in some cases, international law can be a preferable way for all the parties to a conflict to resolve their differences rather than continuing to fight. This post briefly traces the history of international courts’ hopes to bring peace (particularly international criminal courts); notes some of the structural limitations that may limit their ability to fulfill those ambitions; and then suggests some situations in which international courts may assist in peacemaking.
Of course, international courts may do other kinds of good in situations of armed conflict. They can assist in bringing perpetrators of serious crimes to justice; hold States responsible for internationally wrongful acts; provide reparations to victims; and, if they hold a credible process and make rigorous findings, assist in combating the denial of crime. Those are valuable projects and really the core functions of any court. Much can be written about them, and much has been. Here, however, I will set those goals aside to focus where the modern project of international criminal justice began: trying to use justice to advance international peace.
The Goal of Peace Through Courts
In 1993, the United Nations Security Council established the first of the contemporary international criminal courts: the International Criminal Tribunal for the former Yugoslavia (ICTY). In its decision to establish the ICTY, the Security Council determined that reported atrocity crimes in the former Yugoslavia constituted “a threat to international peace and security” and that the establishment of a tribunal to prosecute those responsible for such crimes would “contribute to the restoration and maintenance of peace.”
Several of the subsequent international criminal courts have been established using similar language. For instance, the Security Council resolution establishing the International Criminal Tribunal for Rwanda (ICTR) proclaimed that establishing the ICTR would “contribute to the process of national reconciliation and the restoration and maintenance of peace.” The drafters of the Rome Statute that established the International Criminal Court (ICC) stated that atrocity crimes “threaten the peace, security and well-being of the world.” In inviting the establishment of what became the Special Court of Sierra Leone, the Sierra Leone government told the U.N. that it was necessary to establish “a strong court in order to bring and maintain peace and security in Sierra Leone and the West African region.”
Practice has been more complicated. To take a recent example, the ICC has been investigating allegations of crimes in the Darfur region of Sudan for twenty years. A first conviction was entered at trial in October 2025, covering some of the crimes committed in the area in 2003 and 2004. That conviction is now pending appeal. But in the few weeks following the conviction, not only did fighting rage on in the same area of Sudan, but evidence prompted fresh allegations of atrocity crimes from around the world.
Indeed, when ICTY’s President Judge Carmel Agius addressed a conference in Sarajevo in 2017 that was evaluating the Tribunal’s legacy, he focused more on justice than peace, telling the audience that the ICTY “[gave] you the truth about what happened” but that “we are not offering reconciliation… All the citizens in the countries in the region have the responsibility for reconciliation.”
Structural Limitations
It is no surprise that international courts don’t typically bring an end to war. Political science students learn early that courts are the “least dangerous” branch of government, with “no influence over either the sword or the purse.” International courts are even more dependent on their moral suasion: not only do they control neither sword nor purse, but they do not even have the backing of coordinate branches of a government as a domestic court may. In short, although the courts have fine lawyers, those they seek to regulate usually have a decided advantage in both guns and money.
Aside from that power imbalance, several legal hurdles limit courts’ efforts to end war.
First, often international courts have jurisdiction over crimes committed during wars, but not over parties’ decisions to start or end them. As a result, if parties to a conflict are following the law of armed conflict (LOAC) (or investigating alleged violations by their own servicemembers), international courts may have no justification to intercede in the conflict at all. (The recently-established Special Tribunal for the Crime of Aggression in Ukraine does have jurisdiction over allegations that a war was started unlawfully, and the ICC may have jurisdiction over similar allegations if both the aggressor and victim states have accepted its jurisdiction over the crime of aggression.)
Second, even when it comes to crimes committed during war, proving beyond a reasonable doubt whether crimes have been committed and who is responsible may take significant time, often extending until after the end of the war. Access to crime sites, witnesses, and internal records from perpetrator groups may not be immediately available, and careful prosecutors will focus their limited resources on the strongest and best-evidenced cases. Convictions on such grave charges will remain important whenever they are entered, of course, but if courts often cannot reliably prove whether particular crimes have been committed (or LOAC was violated) until after a war has ended, then they cannot use making such findings to help facilitate the end of war.
And third, the demands of judicial legitimacy limit courts’ ability to seek peace: law demands that the guilty be convicted, those whose guilt has not been conclusively proven be acquitted, and defendants’ fair trial rights be respected throughout the process. These demands are particularly forceful in cases where the allegations are as serious as jus in bello violations, and require a court to respect the fair and just outcome of a trial even if it is not the best outcome for peace and stability.
When International Courts Can Help
Still, these challenges do not mean that international courts can play no role at all. Practice suggests three types of situations where courts may help bring wars to a close.
In the first (and most common) situation, courts can be a peaceful way for parties to resolve some parts of the disputes that led them to resort to force. Most contemporary conflicts do not end with unconditional surrender. They end with negotiations between parties that each have remaining goals and grievances, such as in the example of Colombia below – negotiations that may include not just the warring parties, but also civil society and those harmed by the conflict. Sometimes, those grievances can be channeled into a mutually acceptable dispute resolution mechanism, whether that is a criminal or civil law process, that all parties prefer over continuing to settle their grievances by force.
For international courts to make this kind of contribution to peace, international justice practitioners must be humble, creative, and fair. They must be humble in letting the design of a justice process truly be locally led; creative in thinking flexibly about what justice might look like in a particular situation and trying to work with the most affected parties to develop bespoke, locally appropriate solutions that satisfy those different parties’ widely different goals; and fair so that the parties truly believe that the eventual justice process will be objective, led by the evidence, and not stacked against anyone. For instance, while the ICC was engaging in a “positive complementarity” process in Colombia, the conflict there ended with a peace treaty. As part of the agreement, the parties agreed that those allegedly responsible for conflict-related crimes would be prosecuted in a new domestic institution, which envisioned very lenient sentences for defendants who acknowledged their responsibility for crimes. The ICC accepted this arrangement and did not pursue an investigation or charges in the Colombia situation.
In the second kind of situation, in very specific circumstances, international criminal courts may be able to help end wars by limiting the power of those who would re-start or continue wars. This contribution is only possible when a prosecutor has sufficient evidence to believe she can prove that those who would re-start or continue a war were also legally responsible for the commission of crimes during the war; and the prosecutor seeks to do so before a court that has sufficient influence over those defendants’ forces (or their allies) that an indictment would limit or remove the defendants’ power to continue (or re-start) the war by rendering them unable to continue to lead. In these special circumstances, a court’s work can make a big difference.
Third, in some narrow situations, parties to a conflict may have more incentives to cooperate with an international court than to continue to fight. Perhaps a party to a conflict seeks support from a State or international organization that prioritizes cooperation with the court. Perhaps a party expects the court to validate claims brought by members of their group. Perhaps they seek international recognition. Perhaps they are simply tired of bloodshed.
Many have hoped that courts can contribute to ending war in another fundamental way: that the prospect of punishment would deter individuals or States from engaging in unlawful war or unlawful conduct during war. It is possible some States or individuals have been deterred, though it is hard to prove. But generally, successful deterrence requires a likelihood that offenders will be punished. International courts cannot provide that likelihood today and do not appear likely to do so anytime soon. Instead, this year, the international courts will likely have no cases at all which allege that particular wars were unlawful, and the number of active cases alleging crimes during war in all the international courts combined will likely be in the single digits. Such a small number of cases is very unlikely to have the deterrent impact that international courts’ most ambitious advocates aspire to achieve.
Conclusion
International courts primarily exist as forums to seek justice under the lex lata, within the powers and limitations given to them by States. An effective, responsible court can contribute to mitigating the harms of conflict by doing its job professionally. But most often, the court’s contribution will be mitigation, not demilitarization.
In some instances, however, an international court that treats the parties to a conflict and the communities that are affected as real partners and seeks to help develop justice processes that are truly acceptable to all those concerned may be able to help bring an end to the fighting by helping participants choose law over war. Indeed, with fewer cases in trial, helping parties find creative solutions may be the biggest contribution courts can make to the cause of peace.
