Following years of negotiations aimed at establishing a permanent international tribunal to punish individuals who commit genocide and other serious international crimes, the United Nations General Assembly convened a five-week diplomatic conference in Rome in June 1998 "to finalize and adopt a convention on the establishment of an international criminal court".[7][8] On 17 July 1998, the Rome Statute was adopted by a vote of 120 to 7, with 21 countries abstaining.[5] The seven countries that voted against the treaty were Iraq, Israel, Libya, the People's Republic of China, Qatar, the United States, and Yemen.[5]
Article 126 of the statute provided that it would enter into force shortly after the number of states that had ratified it reached sixty.[3] This happened on 11 April 2002, when ten countries ratified the statute at the same time at a special ceremony held at the United Nations headquarters in New York.[9] The treaty entered into force on 1 July 2002;[9] the ICC can only prosecute crimes committed on or after that date.[10]
As of October 2009, 110 countries have ratified or acceded to the Rome Statute, including all of South America, most of Europe, and roughly half the countries in Africa.[2][11]
A further 38 states have signed but not ratified the treaty;[2] the law of treaties obliges these states to refrain from “acts which would defeat the object and purpose” of the treaty.[12] Three of these states — Israel, Sudan and the United States — have "unsigned" the Rome Statute, indicating that they no longer intend to become states parties and, as such, they have no legal obligations arising from their signature of the statute.[2][13][14]
Any amendment to the Rome Statute requires the support of a two-thirds majority of the states parties, and an amendment will not enter into force until it has been ratified by seven-eighths of the states parties.[15] Any amendment to the list of crimes within the jurisdiction of the court will only apply to those states parties that have ratified it.[15]
The states parties are due to hold a Review Conference in the first half of 2010 to consider amendments to the statute.[16] The Review Conference is likely to adopt a definition of the crime of aggression, thereby allowing the ICC to exercise jurisdiction over the crime for the first time.