The US has found itself in an unenviable position regarding Saddam Hussein. It would have been far more convenient, from their point of view, if he had died during the initial fighting concomitant to the invasion – I am sure that is why they expended considerable resources on trying the achieve that end.
However, having survived and then subsequently being captured, he was always bound to be a problem for them. Firstly, there was the problem of bringing him to some sort of justice – either in Iraqi courts, in US courts or in an international court. As the US continues to ignore the ICJ, the Iraqi courts always seemed the most likely venue – but without using the independent ICJ, it was always going to be open to accusations of being victor’s justice.
Secondly, once the inevitable guilty verdict had been found, there was the problem of what to do with him. Alive, albeit in prison, he could always remain the focus for protest and the hopes of his sympathisers. Dead, he has the potential to be seen as a victim or martyr, particularly by the Palestinians whom he supported. At least, after death, he is unable to make pronouncements, lead protest or be a general pain in the backside for the Americans and the Iraqi government.
The question must be: is it right to kill someone simply for reasons of political expediency? Surely, by doing so, the US and Iraqi authorities (and, by association, the British government with its so-called ethical foreign policy) sink to the same level as the dictator who also killed when it was expedient to do so. (And, is it right to produce television footage of his death for publication? Surely that is a breach of the Geneva conventions, although I suspect the Americans would argue that they do not apply in this case).