By Paul Reynolds
World affairs correspondent BBC News website
Charles Taylor at an earlier court hearing
The trial of former Liberian President Charles Taylor in The Hague, starting on Monday, marks another stage in the world's efforts to bring crimes against humanity to book.
There is still some way to go.
The efforts have progressed only fitfully since the Nuremberg trials of the Nazi leadership after World War Two.
They took significant steps forward with the UN-mandated special tribunals for the former Yugoslavia and Rwanda.
And an International Criminal Court (ICC) to try people accused of war crimes and crimes against humanity was set up by a treaty that came into force in 2002.
However, the ICC is boycotted by the United States and the Taylor trial is not being held under its jurisdiction, partly because it was set up too late.
The hybrid court
Instead, a hybrid court has been convened, called the Special Court for Sierra Leone. The charges result from the support Charles Taylor allegedly gave to rebel factions in Sierra Leone. It is the first time that a former African head of state has faced such a trial.
The special court has been approved both by the UN and the government of Sierra Leone and it sits in The Hague (in ICC premises) because of the risks that the trial might lead to tensions within Sierra Leone itself. The UN and the government of Sierra Leone appoint the judges.
The British government has offered to imprison Mr Taylor if he is convicted.
Unlike the Yugoslavia and Rwanda tribunals, the UN does not fund it and it relies on governments - mainly the US, UK, the Netherlands and Canada - for support. It is currently asking for more cash to enable it to complete the Taylor trial, which is expected to last for a year to 18 months. That would be quite quick in international terms. The Milosevic trial went on for four years and the accused died in custody before it finished.
'Strong signal' sent by trial
Nevertheless, the Taylor trial is characterised by Human Rights Watch as an important moment that "sends a strong signal that no one is above the law."
The chief prosecutor, a former US federal attorney from Iowa, Stephen Rapp, who was a prosecutor in the Rwanda tribunal, told the BBC in an interview in March: "This is an enormous test of international justice."
Mr Taylor faces 11 charges. These relate to terrorising the civilian population, murder, sexual violence (rape and sexual slavery), physical violence (cutting off limbs), using child soldiers (under the age of 15), enslavement (forced labour) and looting.
The issue of linkage
The key point in the trial will not be whether he committed these acts himself.
The argument will be about whether he ordered, supported or condoned such acts. The former president will argue that he did not.
Use of boy soldiers is one of the charges against Taylor
The indictment for each charge alleges that the acts were committed by people who were "assisted and encouraged by, acting in concert with, under the direction and/or control of, and/or subordinate to the accused".
Stephen Rapp said: "The case will turn on the linkage between him and the forces that directly committed these crimes. We have strong evidence to show that. Witnesses will tie Charles Taylor to the crimes."
The Libyan connection
One aspect of the case is that Mr Taylor and his alleged partner-in-crime Foday Sankoh, the now deceased head of the Revolutionary United Front, are said in the indictments to have met at a training camp in Colonel Gaddafi's Libya in the 1970s. Sankoh later paid for weapons from Charles Taylor with diamonds.
The colonel is now a favoured ally of the West following his decision to give his nuclear programme. It was ironic that only last week, on his farewell trip to Africa, the British Prime Minister Tony Blair called on the former revolutionary on his way to Sierra Leone, whose civil war he helped to stop by sending in British troops in 2000.
The question of Iraq
The Taylor trial does not come under the ICC, but one question often asked about the ICC itself is why it has not acted against President Bush and Prime Minister Blair for their decision to invade Iraq in 2003 and for crimes allegedly committed during and after the invasion.
The answer was given in a letter from the chief prosecutor Luis Moreno-Ocampo in February 2006.
In the letter, he says that while the court does in principle have jurisdiction over crimes of aggression, such crimes have not been defined by treaty and until they are, the court cannot act.
"The International Criminal Court has a mandate to examine the conduct during the
conflict, but not whether the decision to engage in armed conflict was legal," he wrote.
As for the conduct of the war, he concluded: "The available information did not indicate intentional attacks on a civilian population."
He accepted that there had been civilian deaths, but concluded that "the situation did not appear to meet the required threshold."
In the meantime, the ICC is pursuing cases involving Joseph Kony, leader of the Lord's Resistance Army in Uganda, Thomas Lubanga, former leader of a militia in the Democratic Republic of Congo, a Sudanese minister and a Janjaweed leader over Darfur and killings and rape in the Central Africa Republic.