Crime of Aggression, International Law and the Chilcott Inquiry

Yesterday, two international lawyers who had held senior positions in the British government at the time of the Iraq invasion testified before an official inquiry that they considered the acts of the British government to be illegal. See the account in today's Guardian. Elizabeth Wilmshurst, who had been deeply involved in negotation of the Rome Statute of the International Criminal Court, courageously resigned when the advice was dismissed and the British government decided to proceed with its American partners. In addition to testimony by Elizabeth Wilmshurst and Sir Michael Wood, who had been the chief legal advisor, memos written at the time were revealed to the public for the first time during yesterday's hearing.
On 24 January 2003, Michael Wood wrote a memo because Jack Straw had told US vice-president Cheney that Britain would 'prefer' that the invasion be authorized by a Security Council resolution, but that it would be 'OK' if they tried and failed to get one 'à la Kosovo'. I note in passing that in 1999 no resolution on Kosovo ever was put to a vote in the United Nations Security Council.
In his memo to Straw, Michael Wood wrote: 'To use force without security council authority would amount to a crime of aggression.' Straw apparaently replied: 'I note your advice but I do not accept it.'
If Wood is correct, and I think that he is, then Straw (and Blair) committed the crime of aggression. But can they be prosecuted for this?
Although the International Criminal Court continues to wrestle with defining the crime of aggression, for the purposes of an amendment to the Rome Statute that will enable it to actually prosecute the crime, there can be no doubt that the crime of aggression exists under customary international law. This has been held by the British courts. It seems preposterous to claim that the crime of aggression existed at Nuremberg and Tokyo (it was then called crimes against peace) , but that it does not exist today because there is no definition in the Rome Statute.
The difficult issue is not defining the crime but finding a court with jurisdiction over it. The House of Lords has already taken the view that British courts do not have jurisdiction to prosecute the crime of aggression. George Monbiot, the Guardian columnist, has been raising funds for a prosecution of Blair. I hope he refunds their money back when he realises that this is a dead end.
The fact that the International Criminal Court cannot actually prosecute the crime of aggression, however, does not mean that this is irrelevant to its work. It arises indirectly, and provides a route to litigate these issues and, I think, hold Blair and Straw accountable.
The Court's Statute adopts a concept of criminal enterprise (art. 25(3)(d)) by which an individual is punishable by the Court who 'contributes to the commission or attempted commission' of war crimes, crimes agianst humanity and genocide 'by a group of persons acting with a common purpose. Such contribution shall be intentional'' and shall be 'made with the aim of furthering the criminal activity or criminal purpose of the group, where such activity or purpose involves the commission of a crime within the jurisdiction of the Court' (my italics). This is the entry point for the crime of aggression in the work of the International Criminal Court.
There is a good case to be made that Blair and Straw were part of 'a group of persons acting with a common purpose' whose activity involved 'the commission of a crime within the jurisdiction of the Court', namely, the crime of aggression. Article 5(1) of the Statute states that 'the crime of aggression' is a crime within the jurisdiction of the Court. Although article 5(2) says that temporarily the Court cannot exercise jurisdiction over the crime of aggression, this is not what it would be doing if it proceeded against Blair and Straw for war crimes committed pursuant to a common purpose to commit aggression. All this does is make effective the words of article 5(1), which describe the crime of aggression as a crime within the jurisdiction of the Court. These same words are used in article 25(3)(d).
The Court can exercise jurisdiction over war crimes committed in 2003. It has jurisdiction over Blair and Straw because they are nationals of a State party. And it can punish those who were part of the 'common purpose' or criminal enterprise to commit aggression even for war crimes committed by individuals who escape its jurisdiction, such as American nationals.
The Prosecutor of the International Criminal Court has already been dismissive of appeals that he investigate British war crimes in Iraq, although he has acknowledged that there is good evidence some took place He has also suggested that Britain is dealing with them before its own courts.
But Britain isn't dealing with the masterminds of the joint criminal enterprise to commit aggression. They are liable under the Rome Statute to the extent that war crimes were committed pursuant to this joint criminal enterprise. In other words, if either British or American troops committed war crimes, then Blair and Straw should be liable for prosecution by the Court under article 25(3)(d).
In his 2006 statement, the Prosecutor said he would not proceed against the British troops for what he suggested were isolated war crimes, because they were not serious enough. Perhaps he has a point here. But he might reconsider this with respect to Blair and Straw, especially given the fact that according to yesterday's testimony they defied advice from their own experts who told them that they would be committing the crime of aggression by invading another country without Security Council authorization. That strikes me as 'serious enough'.