In his recent diatribe against the International Criminal Court, U.S. National Security Advisor John Bolton might have given some the impression that the International Criminal Court had somehow conjured up international law, writes Eric Witte.

That is not the case. Instead, the court is the keystone of a nascent system of institutions enforcing already-existing laws: the international conventions, which are signed by the community of nations; and customary international law, which criminalizes genocide, war crimes, and crimes against humanity.

Whatever the criticisms of the still-evolving International Criminal Court’s performance, the imperative of holding perpetrators to account for the gravest of crimes—crimes for which there is no statute of limitations—continues to command political attention around the world.

In Gambia, for instance, the government is grappling with how to hold a former president to account for torture and other atrocities. Mexico’s president-elect, meanwhile, has agreed to explore the creation of an international mechanism to investigate and prosecute crimes against humanity and other serious crimes arising from the country’s conflict with criminal gangs. In South Sudan, a new peace deal has recommitted warring factions to the creation of a court, backed by the African Union, which would address atrocities by all sides. Similar initiatives are under discussion to address appalling crimes committed in such places as Syria, Sri Lanka, and Myanmar.

Some situations fall outside the International Criminal Court’s jurisdiction. Others exceed the capacity of The Hague–based court, which was always envisioned as a last resort. It is preferable to hold perpetrators to account in local or regional courts—places that are more accessible to the communities where the atrocities occurred.

Criminal courts for the former Yugoslavia and Rwanda were first set up on an ad hoc basis in the 1990s, before the International Criminal Court’s launch in 1998. Other kinds of tribunals have been created since, such as the Extraordinary African Chambers in Senegal, which convicted former Chadian dictator Hissène Habré of crimes against humanity, war crimes, and torture. Domestic trials have applied international law too, sometimes with international support, as in Guatemala and the Western Balkans. Some accountability institutions have included corruption or other serious crimes in their mandates.

Over the past 35 years, since the end of the Cold War opened political space throughout much of the world, many different models have been tried, with varying degrees of success. In an effort to make sense of these diverse experiences, the Open Society Justice Initiative embarked on a major study of what has worked and failed.

Our new report, Options for Justice: A Handbook for Designing Accountability Mechanisms for Grave Crimes, looks at 33 different approaches in 29 countries in order to distill lessons and considerations for the design of new bodies. The models examined include purely domestic trials (as in Argentina), hybrid models (where international and local staff and judges work together, as in Sierra Leone), and the ad hoc tribunals for Rwanda and the former Yugoslavia that marked the birth of the modern movement for accountability.

The handbook focuses on questions of design, not operation. It sets out some of the big questions that need to be answered, starting with the mechanism’s purpose and scope. Should the proposed mechanism be concerned with investigation and prosecution? Is it meant to achieve accountability for a defined set of cases, or is it more ambitious? Does it, for example, intend to strengthen the justice system and respect for rule of law as a whole?

The handbook identifies nine such key questions, including the mechanism’s jurisdiction, its relationship to the domestic judicial system, the basis of its authority, financing, oversight, and location.

There is no simple formula for creating a new accountability mechanism. Some across-the-board lessons include a need for early and robust outreach to affected communities, a need for strong defense structures to uphold fair trial rights, and the imperative of robust internal and external oversight to foster efficiency and avoid scandal.

Beyond these clear lessons, most design decisions entail difficult tradeoffs. For example, local trials have many advantages but may be impossible because of security threats to the process. Victim demands for comprehensive prosecutions may be in tension with limited funding. The introduction of international judges or staff may promise greater objectivity and technical expertise but could undermine the mechanism’s legitimacy in the eyes of some or even most local stakeholders.

There are costs, benefits, and even contradictions in most design choices. With Options for Justice, accountability advocates around the world have a tool to inform plans for new mechanisms based on a fuller appreciation of lessons from previous models. If they can do this, and tailor a new generation of accountability mechanisms to individual contexts, they will fortify the system of international criminal justice.

ERIC WITTE IS THE SENIOR PROJECT MANAGER ON NATIONAL TRIALS OF GRAVE CRIMES FOR THE OPEN SOCIETY JUSTICE INITIATIVE

Open Society Foundations