On 20 November 1945, the criminal trial of 23 senior Nazis opened in courtroom 600 of Nuremberg’s Palace of Justice. Hermann Goering, Albert Speer and Hans Frank were among those in the dock for a variety of horrors, in a case that was cobbled together at great speed.

It was a unique moment, the first time in history that individual leaders of a sovereign nation had found themselves before an international criminal court. The day heralded the promise of a new world constructed on the pillars of justice and law, a world that seems as far away as ever in the light of the current situation in Syria and the barbaric events in Paris.

Britain favoured execution over Nuremberg trials for Nazi leaders Read more

“Four great nations, flushed with victory and stung with injury stay the hand of vengeance and voluntarily submit their captive enemies to the judgment of the law,” chief prosecutor Robert Jackson told the eight judges. That the defendants were not simply lined up and shot, as Winston Churchill would have preferred, reflected, as Jackson put it, “one of the most significant tributes that power has ever paid to reason”. He recognised the privilege, responsibility and risks of such a trial, that the wrongs to be punished were “calculated … malignant … and … devastating”, articulating a hope that civilisation might never again tolerate such actions being ignored or repeated.

We need no reminding that the wrongs have continued across time and place, by different and terrible means, and continue to make clear that the aspirations reflected in the trial’s opening would not easily be fulfilled by the simple expedient of putting in place new laws and institutions. A glance across our world today reveals the scale of the struggle we face. Impunity reigns. The state of our world suggests that the memory of the past, and the lessons we hoped to learn, have been permitted to slip from view.

Yet it cannot be said that our present plight is entirely for want of effort, reflecting our desire to tame power by the force of reason and law. Over five long decades after Nuremberg, politicians, diplomats and lawyers struggled to put in place the semblance of an international justice system. New international crimes have been agreed – genocide, crimes against humanity, aggression – and in the 1990s new courts were finally established. Responding to the horrors in the former Yugoslavia and Rwanda prompted the Security Council into action. “Too little, too late,” some said; “better than nothing,” others responded.

In 1998, 160 states gathered in Rome to agree on the Statute of an international criminal court, the culmination of five decades of painful negotiations. The court sits in The Hague with 18 judges speaking to the possibility of justice, dispensing a little here and there, provided that the great powers will give them the nod. The court’s limited track record – some speak of a crisis – shows how far we are yet to travel, how the constraint of power by international law remains a work in progress.

These failings raise fundamental questions, as an embryonic global justice system is constructed on the anvil of atrocity. Is that which we have today better than nothing? Does the illusion of justice do more harm than good? And, as I have occasionally wondered, did the ICC come too soon?

Africa offers a stark illustration of the challenges. In June the South African government ignored an order from the ICC to arrest Sudan’s President Omar al-Bashir - for alleged genocide and war crimes in Darfur - as he visited Pretoria, provoking a crisis also with its own courts, which ordered that Bashir not be allowed to leave. The decision reflected a wider problem, one that is barely addressed in polite company: every one of the 23 cases today at the ICC involves Africa, as though that continent has a monopoly on international crime. Yet we know that not to be the case.

Why South Africa is wrong to leave the international criminal court Read more

The Nuremberg trials have long faced the criticism of lopsided justice, the whiff of “victor’s justice” in which the powerful use the law to rein in the weak. “Laws are spider webs through which the big flies pass and the little ones get caught,” Honoré de Balzac wrote. That whiff continues to permeate today: what accountability for those leaders who joined in authorising an illegal war in Iraq in 2003, or the lawyers and others who authorised waterboarding or other torture at Guantánamo, Abu Ghraib and Bagram? The efforts of such individuals are repaid with lucrative consultancies, judgeships, academic position at prestigious universities, and partnerships in multinational law, an affront to the aspiration of confronting impunity.

Our world is a far cry from the one that Robert Jackson might have hoped for when he stepped up to the lectern in Nuremberg’s courtroom 600. “The common sense of mankind demands that law shall not stop with the punishment of petty crimes by little people,” he asserted. “It must also reach men who possess themselves of great power.”

That it does not do so reveals the idea of international justice to be a work in progress. The law alone will not make war impossible, or stop killings and other crimes, but it can provide a framework for the determination of what is right and wrong, a means of proclaiming the rights of individuals and groups against barbarism. It is easy to forget that in the period before Nuremberg no such rules existed, that governments were free under international law to treat their citizens as they wished. Easy, too, to embrace the instinct to “take out” those responsible for beheadings in Syria, or mass murder on the streets of Paris, or other horrors that may be yet to come.

International courts are symbols of a commitment to enforce the rules that have been put in place by judicial means, a means of encouraging national courts to engage more actively. However imperfect, Nuremberg’s legacy is one of potential, for the idea of accountability, for the hope that we shall not become like those who seek to destroy us, and for the memory of justice. It’s going to be a long game, as Paris makes clear.

• Philippe Sands’s film My Nazi Legacy: What Our Fathers Did opens at Picturehouse Central and Home Manchester today