Background: International criminal court

How the court in The Hague, which began its historic first trial today, came into being

For human rights advocates, the creation of the international criminal court represents the fulfilment of a goal that began with the Nuremberg and Tokyo tribunals for Nazi and Japanese war criminals.

Established in 1998 by an international treaty in Rome, the ICC was created to provide justice for genocide, crimes against humanity and war crimes when national systems fail.

It is a court of last resort for victims, a permanent instrument of justice to replace the ad hoc UN tribunals set up to deal with Yugoslavia and Rwanda.

One hundred and eight states have ratified the Rome statute, but there are notable absentees - the US, Israel, China and India. Britain opposed the ICC until Tony Blair replaced John Major as prime minister in 1997.

Questions over the court's legitimacy have inevitably arisen because it has not been ratified by key parties.

The US insists it is not trying to undermine the court, but just attempting to protect US personnel abroad from an "unaccountable" prosecutor and "frivolous" cases.

Russian actions in Chechnya, like Israel's in the occupied Palestinian territories, will also be off limits for the foreseeable future, risking accusations of selective justice.

With Barack Obama in the White House, the US is likely to tone down its opposition, but antipathy towards the court is so entrenched that hopes for American ratification remain slim.

The best that human rights advocates can hope for is a stab at ratification in a second term if Obama is re-elected.

The ICC depends heavily on the goodwill of the UN security council. It was able to proceed on Darfur, where serious human rights violations have taken place, only after the US agreed not to use its veto. It did so after receiving guarantees that US citizens in Sudan would be exempt from prosecution.

The security council can ask the ICC to launch investigations or the ICC prosecutor can decide independently to start investigations, but prosecutions have to be approved by a panel of judges.

The decision by Luis Moreno Ocampo, the ICC prosecutor, to issue arrest warrants for President Omar Hassan Ahmed al-Bashir of Sudan on charges of crimes against humanity and genocide raised many eyebrows - evidence, if any was needed, of the political minefields the court has to negotiate.

The ICC prosecutor has opened investigations in the Democratic Republic of the Congo, Uganda, Sudan and Central African Republic, and the court has four suspects, all of them alleged warlords from Congo, in custody.