The past month has brought milestones but also new challenges to the Special Tribunal for Lebanon. The tribunal recently released the names of four men wanted for the assassination of former Lebanese prime minister Rafiq al-Hariri and 22 others in 2005.

The suspects are Mustafa Amine Badreddine, a senior figure in the Shiite militant group Hezbollah who is suspected of making the bomb that blew up the U.S. Marine barracks in Beirut in 1983; Salim Ayyash; Assad Sabra; and Hassan Anise. The unsealing of the long-awaited indictments triggered a 30-day period during which the Lebanese government is required to serve arrest warrants, but Lebanese authorities informed the court last week that they are unable to arrest the four or serve the indictments. Hezbollah leader Hassan Nasrallah has vowed to thwart the suspects’ arrest, and this opposition is no small threat. The previous Lebanese government, led by Saad Hariri, son of the slain prime minister, collapsed in January after Hezbollah ministers and their allies left the cabinet to protest the government’s support for the tribunal.

The special tribunal was established in 2007 by the U.N. Security Council at the request of Lebanon’s then-prime minister. The court is charged with rendering justice for the massive bombing that rocked the nation in February 2005. Although Lebanon is no stranger to extreme violence, Hariri’s assassination rekindled the tension between Lebanon’s various factions that had been seething just under the surface. Lebanon sought to recover by turning a corner from political violence to the rule of law. It established a tribunal based in Lebanese law, with judges from Lebanon and other countries, that operates with a U.N. mandate. Knowing how perilous this project would be, the government signed on to an internationally sanctioned court that could transcend taint or accusations of sectarian partiality.

As the tribunal’s president, the noted Italian jurist Antonio Cassese, pointed out in a column last month, Lebanon’s government has aimed “to uphold and to practice the principle of judicial accountability for those who grossly deviated from the rules of human decency” and “to entrench the notion that democracy cannot survive without the rule of law, justice and respect for fundamental human rights.”

This is the first time an international tribunal has been created to deal with an act of terrorism. Yet while the tribunal has novel aspects, the indictments present challenges that are all too familiar to us. We served as chief prosecutors of international tribunals established since the mid-1990s. We are intimately familiar with the challenges pointed up by the mere existence of such courts — and with the values at stake in achieving success. We have closely followed the tribunal’s work and challenges, and understand that, now more than ever, this tribunal will need the unwavering support of the international community.

International courts such as this tribunal have no capacity to arrest their suspects; they must rely on individual countries to do so. The International Criminal Tribunal for the former Yugoslavia, for example, would not have been able to deliver justice to survivors of “ethnic cleansing” and genocide if individual governments had not made concerted efforts to ensure that suspects were found, arrested and delivered to trial.

One of us served as chief prosecutor of the Special Court for Sierra Leone, a tribunal that, like the Lebanon tribunal, is a blend of national and international elements. When the Sierra Leone court’s indictment of Liberia’s then-president, Charles Taylor, was unsealed in 2003, some predicted that step would derail peace negotiations. They were wrong: Although not its aim, the indictment of Taylor facilitated peace in war-torn Liberia and maintained peace in Sierra Leone. Earlier, the indictment of Radovan Karadzic by the tribunals for the former Yugoslavia was an essential precursor of the 1995 Dayton Agreement that silenced the guns in that region of Europe.

We know what it means to face long odds and extraordinary defiance in the pursuit of international justice. We succeeded in beating those odds, with historic results, because the international community supported us and governments honored their obligations despite formidable pressures. The Special Tribunal for Lebanon deserves no less.

David M. Crane, a professor at Syracuse College of Law, is a former chief prosecutor of the Special Court for Sierra Leone, a U.N.-sponsored international tribunal. Carla Del Ponte is a former chief prosecutor of the International Criminal Tribunals for the former Yugoslavia and for Rwanda.