Why I had no choice but to spurn Tony Blair - The Guardian 2nd September. Tutu went further and argued that Blair and Bush ought to be tried by the International Criminal Court - The Telegraph 2nd September - Archbishop Tutu - Try Blair for War Crimes. The actions of Blair and Bush in relation to Iraq will always be controversial and debate continues as to whether the invasion of Iraq (a sovereign State) in 2003 was lawful. However, this post is not concerned with either the legality or the "morality" of the war but only with the question of the ICC's jurisdiction since trials are only possible where the court has jurisdiction.
The United States of America has not accepted the court's jurisdiction and also Iraq is not a States Party. The United Kingdom became a States Party on 4th October 2001. The court only has the jurisdiction granted to it by the Rome Statute on the International Criminal Court - see ICC website - jurisdiction and Court's Statute.