The trial and execution of Charles I was followed by the dictatorship of Oliver Cromwell and the Restoration of Charles II. It was not until 1689, 40 years later, that England reached a stable and liberal constitution. The execution of Louis XVI was followed by the Terror that did much to destabilise and discredit the French Revolution.

On the other hand, the Nuremberg trial of the Nazi leaders, which ended in the execution of the leading surviving German war criminals, proved to be the foundation of a new and peaceful Germany. There were similar trials and executions in Japan, followed by a similar successful reconstruction. Obviously, there is a risk that the decision to hang Saddam Hussein will make him stronger in death than he is in life, at least among Sunni and Baathist supporters of his regime. Dead tyrants can become martyrs.

Fortunately, the question is not one to be decided by the Allied governments. The decision is one for the courts of Iraq and the Iraqi Government, not for the United States or Britain. Sir Menzies Campbell, the Liberal Democrat leader, thinks that Saddam should be sentenced to life imprisonment; so apparently do the Scottish Nationalists. It is not their decision, any more than it is the decision of Tony Blair or George Bush.

Anyone is entitled to take the view that capital punishment is always wrong. However, that is not the view of the majority of Iraqis, nor is it the teaching of the Koran or of Sharia. Nor, of course, has it ever been the view of Saddam himself. The European Union is indeed a zone that is free of capital punishment, but the European nations almost all felt that capital punishment was justified, or inevitable, as a punishment for genocidal crimes in the Second World War.

Like many people, I am now opposed to capital punishment, but at the time of the Nuremberg trials I thought it was justified. In the early 1960s I thought the Israelis were right to kidnap, try and execute Adolf Eichmann, the chief bureaucrat of the Holocaust. I suspect I might feel the same about Saddam if I were an Iraqi whose family had suffered under his regime. An individual may be able to forgive, but there are some crimes so terrible that a nation cannot be expected to forgive.

Trials for war crimes, or the trials of deposed rulers, are sometimes non-existent and almost always unsatisfactory in some way. So far, the trials of Saddam have not covered most of the worst crimes alleged against him. There are 12 more significant charges. If he were tried on all of them, that would be of great interest to historians, but he might still be shaking his fist at Allah in 2020. It is reasonable that the procedure should reach a decision at this stage. He does have an appeals procedure and there are substantive issues of process to be raised.

Nevertheless, Saddam seems to have had a fair trial, by the standards of these trials. The verdict is in conformity with the evidence, and there are vast quantities of further evidence in reserve. The Kurds and the Marsh Arabs know that he is a mass murderer, because he murdered them by thousands or tens of thousands. In terms of public opinion in Iraq, he was already convicted and there is no reason to think that opinion is mistaken.

However, this may mark a turning point. It is obvious that the decision to hang Saddam is a very important decision, one of the biggest decisions since the invasion. It is also obvious that this is a decision for the elected Government of Iraq.

That may take some time to sink in. I regard Alex Salmond, the leader of the Scottish Nationalists, as one of the brightest people at Westminster. He has an irreverent streak. Yet even he seems not to have understood that the opinions of the Scottish National Party on the sentencing of Saddam are as absurd as the Irish newspaper’s editorial that gave warning to the Tsar of all the Russias that the Skibbereen Eagle had its eye on him.

It does not matter what we think. If the Iraqis decide that a man who used mustard and nerve gas to murder 100,000 Kurds ought to be hanged, that is a matter for them. Their Prime Minister, Nouri al-Maliki, is an independent prime minister. His independence must be respected. In fact, the only plausible threat would come not from the SNP, nor I think from the US State Department. There may well be still some prejudice to Iraq’s independence from Donald Rumsfeld, the Secretary of Defence, and the Pentagon, who have more than 100,000 men in Baghdad and have become accustomed to taking the big decisions about Iraq’s future. I wish one could be sure that the Pentagon had the humility to respect Iraq’s independence, but it is not likely to intervene on this issue.

The decision to invade Iraq in 2003 is now history. Whether it was justified will depend on the emergence of Iraq as an independent democracy. The trial of Saddam has taken place under Iraq law. He has been sentenced to death. The decision to carry out that sentence is in the hands of the Government of Iraq.

This is the process most of us originally hoped for. We have no reason to intervene in a decision that depends on the culture of Islam rather than of Britain. A hundred years ago our forebears would have had no doubt that he should hang. Even today his crimes cry out for retribution.

There is risk in all this. The Sunni community may regard Saddam as one of their historic defenders against Shia militants. They would be wrong, but that could happen. His execution could be blamed on foreign troops, who have become unpopular after three years of occupation. Yet this will be the independent decision of a sovereign government. As such, we have neither the right nor the ability to change it, but would be wise to respect it. This is a step on the road to Iraq’s full independence.

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