Based on recent reports it looks like Colin Powell is practically admitting there were no Weapons of Mass Destruction in pre-war Iraq although this was the primary justification for the US invading the country in an action that has left an estimated 8000 civilians dead. That's quite a number who've lost their lives over a clerical error which happens to have spiralled the US deficit and made a few defence contractors richer.

I was curious as to whether I could look up the definition of “war crime” and see if starting a war for bogus reasons qualifies. My search lead me to the Crimes of War project and an article entitled Who Owns the Rules of War? which had these interesting paragraphs

The enduring law established at Nuremberg has thus turned out not to be the ''crime of aggression'' but a reaffirmation of war crimes as traditionally understood -- with two important innovations made necessary by the Nazi death camps: genocide and crimes against humanity. Nuremberg also had serious gaps. Most significant, it failed to address the terror bombing of civilians and the deliberate consuming of whole cities (Dresden, Tokyo) by fire -- the most enthusiastic practitioners of the latter being the Allies.

The failure to prosecute the Allies for firebombing cities is one of the strongest arguments today for why war-crimes tribunals should not be conducted by the victors. Many regard this argument as so clinching, in fact, that the mere charge of ''victor's justice'' is enough to end debate.

That clarified things for me. The definition and prosecution of a “war crime” is really up to the victors so the answer to my question is that it is highly unlikely that the events leading up to the debacle in Iraq will ever be considered a “war crime”. The rest of the article goes further in convincing me that the term “war crime” is a mostly meaningless phrase which has never been uniformly applied and for which there are very few if any useful metrics.