KAMPALA The United States, wary of politicized investigations into the use of force by countries, said that allowing the International Criminal Court to prosecute crimes of state aggression poses a risk to the court itself.
At a landmark review conference of the ICC in Kampala, delegates are seeking to agree a definition of state aggression and how ICC investigations into the crime, one of four grave crimes the court has jurisdiction over, could be triggered.
The issue has divided delegates and NGOs over fears that giving the court powers to prosecute state aggression -- defined broadly as using force that manifestly breaches the UN charter -- could open it up to criticism of political bias and may again prove too divisive for full agreement to be reached in Kampala.
United States ambassador-at-large for war crimes Stephen Rapp warned late Tuesday about legal uncertainties over state aggression investigations and said that that pushing forward on the issue despite a lack of "genuine consensus" could undermine the ICC.
"What impact might the proposed definition, if adopted, have on the use of force that is undertaken to end the very crimes the ICC is now charged with prosecuting?" he said.
The United States withdrew its support for the ICC under then president George W. Bush in 2002, worried that its troops could face politically motivated prosecutions over unpopular wars, but has more recently started to re-engage with the court.
In Kampala, delegates have praised the work of the ICC and called on states to co-operate fully, but several proposals on how a probe into state aggression could be triggered have been circulating amid heated debate.
What's at stake in an extended ICC mandate is the impact on the use of force, such as NATO's bombing of Kosovo in the 1990s, Tanzania's invasion of Uganda to overthrow Idi Amin or more recently Colombia's raids in Ecuador against FARC rebels.
Security Council member states say ICC probes into state aggression should follow a Council ruling, but groups such as Human Rights Watch say this could hit the ICC's judicial independence.
Rapp also said key aspects of a definition of the crime are still uncertain, stressing that it must be made fully clear what actions are illegal prior to the use of force.
Britain has backed the United States and said any agreement at the conference on an act of aggression must be unanimous. Dutch delegates did not rule out the prospect of a consensus decision.
Richard Howitt, head of the European Parliament delegation to the ICC, told reporters the parliament opposed the use of an "external filter," and decisions on ICC probes into state aggression should rest with the court itself.
Without saying which body should order a probe, Africa Union legal counsel Ben Kioko said investigations should follow an external authority ruling that an act of aggression took place.
Kioko said division over state aggression had hindered international justice developments for much of the 20th Century.
"The expectation that all those differences are going be sorted out in 10 days is very optimistic, but no one expected what happened 12 years ago in Rome (when the ICC founding treaty was signed)," said Bill Pace, convenor of a coalition of NGOs that support the work of the ICC.
(Editing by Giles Elgood)