What does his execution accomplish? Is this really justice or is it revenge? C.S.Lewis has a very interesting essay on the underlying reason for any form of criminal punishment. He argues that society has various reasons for punishing criminals. Revenge is one reason. Rehabilitation is a second reason. Protecting the public from a monster is the third reason and just retribution is the fourth reason.
The first three reasons for punishment do not bring about justice, and lead very easily to an abuse of justice. Revenge merely perpetuates a cycle of violence and bitterness, and therefore perpetuates injustice on a massive scale. Rehabilitation is also a wrong foundational motive for judicial punishment, because if that is the only reason for incarceration you would logically have to keep the criminal locked up until he could prove that he was rehabilitated. Not only would this be a subjective judgment, but it may lead to a much longer prison sentence than would be just. Likewise, if protection of the public is the only reason for punishment, a criminal might be locked up forever–not because of the crime he had committed, but because he was a danger to the public. Therefore, revenge, rehabilitation and protection of the public are inadequate reasons for judicial punishment.
According to Lewis, just retribution remains the only foundation for a justice system that can be as objective as possible. In this scenario criminal A commits crime B and is given sentence C. This treats both the individual and his crime in a fair, objective and dignified way. The state authority could reserve capital punishment as the only fair and objective punishment for a particular crime, but for serious offenders life imprisonment must be the best way for a life to be yielded up in retribution.
They should have locked up Saddam, thrown away the key and given him nothing to eat but Froot Loops.