The dream of creating a permanent court to try the world's most heinous crimes became a reality today, hailed by many as a landmark human rights achievement but rejected by the United States.
Ireland was among 10 nations that brought the total number to ratify a Rome treaty establishing the International Criminal Court to 66 ' six more than needed to bring the treaty into force on July 1st.
Ireland deposited its papers at the same time as nine other nations - Bosnia, Bulgaria, Cambodia, Congo, Jordan, Mongolia, Niger, Romania and Slovakia - so the honour of being the 60th state does not go only to one country.
"The required number of 60 ratifications for the entry into force of the Rome statute has been reached," said chief UN legal counsel Mr Hans Corell to sustained applause. "A page in the history of humankind is being turned."
The tribunal is expected to go into operation next year in The Hague, Netherlands, a belated effort to fulfil the promise of the Nuremberg trials 56 years ago, when Nazi leaders were prosecuted for new categories of war crimes against humanity.
The new tribunal has jurisdiction only when countries are unwilling or unable to prosecute individuals for the world's most serious atrocities: genocide, crimes against humanity, war crimes and other gross human-rights abuses.
Cases can be referred by a country that has ratified the treaty, the UN Security Council or the tribunal's prosecutor after approval from three judges. But the court is not retroactive and cannot probe crimes committed before July 1st.
In a rebuff to its European allies, a major force behind the court, the Bush administration rejected the entire concept of a permanent international war crimes tribunal.
And it is considering withdrawing former President Bill Clinton's signature from the Rome treaty, even though President Clinton did not submit it to Congress for ratification, fearing US soldiers abroad would be subjected to frivolous prosecutions.
(Additional reporting Reuters)