A move by the official prosecutor of the International Criminal Court to secure a warrant for the arrest of the president of Sudan is an unexpected attempt to pin responsibility for crimes against humanity in the Darfur region on the man at the top. It has upset China, Sudan's most influential ally, and drawn an ambivalent response from the United States. But it was the United Nations Security Council that referred events in Darfur to the court. And neither China nor the US, who do not themselves accept the court's jurisdiction, used their power of veto to stop it. China has used its close economic and political links with the Beshir regime to play a leading role in convincing it to accept peacekeepers and in trying to bring the warring parties to the negotiating table. Beijing is understandably concerned that the request for an arrest warrant will provoke its ally and threaten any prospect of a settlement. It is not surprising either that the US, though a strong critic of Sudanese atrocities, gave the news a qualified welcome. The Bush administration opposes the ICC because of fears it could be used to launch politically motivated prosecutions of Americans, for example in relation to the war in Iraq and the 'war against terror'. If the court is to maintain respect for its independence, it must safeguard its reputation against suggestions of political motivation. This is not easy to do, especially when the suspect is a head of state. But the court, in considering atrocities in Darfur, is fulfilling its responsibilities. An arrest warrant can only be granted after an investigation by judges sitting in a pre-trial chamber. This has yet to take place. Just two months ago, the Security Council effectively reaffirmed its confidence in the court by calling on Sudan to co-operate with it. The warrant is unlikely to be served on Sudanese President Lieutenant General Omar al-Beshir unless and until he is overthrown and forced to flee. Its main value therefore may be in the message it sends. For the sake of the long-suffering people in Darfur, it is to be hoped it will have a positive effect.