IF BEING busy is the test, then international justice is in rude health. This week saw a landmark in the short, sputtering history of the International Criminal Court (ICC), an institution based in The Hague that is supposed to be the ultimate resort against infamies which might otherwise go unpunished. On November 22nd, after many procedural twists, the trial began in earnest of Jean-Pierre Bemba, a rich Congolese warlord and the most senior political leader to be detained by the ICC so far. He is accused of war crimes and crimes against humanity—not in Congo, but in the neighbouring Central African Republic, where he intervened on the president's side during a coup attempt. The ICC is also about to name six prominent Kenyans as alleged instigators of the violence that followed the 2007 elections.

Elsewhere in the Dutch city, the tribunal on ex-Yugoslavia will soon have further questions for Radovan Karadzic, political leader of the Bosnian Serbs, about the massacre near Srebrenica in 1995 (see table). Two other special-purpose courts in The Hague will also be busy. One deals with Sierra Leone and is trying Liberia's former president, Charles Taylor. Another is struggling, despite opposition from the armed Shia opposition in Lebanon, to investigate the bomb attack that killed Rafik Hariri, then prime minister, in Beirut in 2005. Most important of all, the United Nations Security Council must decide what to do about Sudan, where president Omar al-Bashir is wanted by the ICC.

Despite all this activity, however, enthusiasm is flagging for the idea of spectacular transnational trials that punish wrongdoers and promote lawfulness and peace. The biggest ad-hoc tribunals, established by the Security Council in the bold and zealous early 1990s, are winding up. The one dealing with ex-Yugoslavia is due to finish its primary trials by 2012. The tribunal trying those responsible for the 1994 genocide in Rwanda, based in the Tanzanian city of Arusha, is drawing to a close.

Both have run up quite a bill, mainly because they had to maintain expensive networks of investigators on the ground. Prosecuting the crimes in ex-Yugoslavia has so far cost around $2 billion. The tribunal for Rwanda spent more than $1.4 billion. When their activities reached a peak in 2004 the two courts were gobbling up about 15% of the UN's entire budget, notes Adam Smith, an American lawyer and diplomat, in a book called “After Genocide”.

Few if any such one-off extravaganzas will be set up again. The newly fashionable approach is “mixed courts”, combining local and global legal expertise, as in Cambodia. Yet the general-purpose ICC is not cheap either, with an annual budget of nearly $150m. Some complain that it offers even less value for money, having so far yielded only a dozen arrest warrants and indictments, all relating to Africa.

The court's supporters argue its very existence has huge indirect benefits: signalling to wrongdoers all over the world that their misdeeds risk retribution and that might does not always equal right. But growth in the court's caseload faces big constraints. Its prosecutor can pursue an investigation only in carefully limited circumstances, for instance at a member country's invitation or at the behest of the Security Council.

In 2005 the Security Council took a fateful step by referring the situation in Darfur to the ICC, which led to the indictment of Sudan's president. It is hard to see that happening again, either. Two permanent council members, Russia and China, are protective of national sovereignty and wary of precedents that undermine it. It therefore looks unlikely that the Security Council would take, say, Sri Lanka's or Burma's leaders to task.

NGOs may have shamed governments into acting over Darfur. But they are hobbled by ideological divisions. For many American human-rights campaigners, the biggest menace is repressive Islamic regimes. At the other extreme Claudio Cordone, senior director of Amnesty International, a campaign group based in London, wants America to investigate the former president, George Bush junior, for ordering the waterboarding of terrorism suspects.

The idea that human-rights abuses and war crimes should be punished gained ground in the 1990s, as democratic regimes replaced authoritarian ones in many parts of the world, notably Latin America. But it is harder to apply in zones of ethnic strife or failed states. From Belfast to the Hindu Kush, conflict zones abound where the only credible interlocutors in a peace process happen to be rebel leaders or warlords. In any effort to broker a political settlement (and NATO's exit) in Afghanistan, few will scrutinise the Taliban's human-rights record too carefully. (Those recently negotiating with a leading Pushtun did not even realise that he was an impostor.)

Still, some close observers of global-justice bodies think the principle of accountability for terrible crimes is now too well established to unravel quickly. The Security Council has recently sent signals that protecting civilians from atrocities will remain one of its chief concerns. And the world's emerging powers are absorbing that ethos as they come to play a more prominent role, says Edward Luck of the International Peace Institute, a think-tank.

Other veterans of UN diplomacy say that governments cannot just sit on their hands when they confront a humanitarian crisis. Activating the ICC, as in Sudan, may sometimes be the least bad choice. Colin Keating, who helped establish the Rwandan and Balkan tribunals and now heads Security Council Report, another think-tank, sees a “high chance” of judicial responses to future crises. And Richard Dicker of Human Rights Watch, a New York-based lobby group, thinks that even in its present mood and make-up, the Security Council could hardly avoid mandating a judicial process if it were presented, once again, with a “situation of unrelenting horror” comparable to Darfur or Rwanda.

Yet the idea that the ICC might be called into a war zone in the absence of any other effective response is troubling. In some parts of the Balkans, international justice helped create peace precisely because it was used in combination with other instruments, from peacekeeping to economic aid. Dishing out indictments, but doing nothing much else, could in some cases be worse than useless.