That was on narrow grounds, involving identification evidence. But in several of the notorious English miscarriages of justice uncovered nearly two decades ago, the grounds on which cases were reopened proved to be much narrower than those on which the appeals were eventually granted. Although we shall never know, it strikes me as very likely that Megrahi's appeal would have been allowed. This would have done far more damage to public confidence in Scottish justice than releasing a man to die of cancer.

But people have short memories. Some seem to have forgotten that prisoners are ever released on licence in Britain. I'm not just thinking of Ronnie Biggs, the train robber freed in England two weeks before Megrahi. Remember the Good Friday agreement, under which hundreds of paramilitary prisoners were freed in Northern Ireland some nine years ago? Governments decided that the move was justified by wider political advantages.

That, of course, was how Megrahi came to be convicted in the first place. He was tried under Scots law at a military base in the Netherlands: the only time that the ordinary courts of one country have sat in the territory of another to try the citizens of a third. 

The whole agreement under which he and his co-accused stood trial was a uniquely political event. Colonel Gaddafi's willingness to sacrifice his senior officials, knowing that they might never be freed, shows how much importance he attached to normalising ties with Britain and the US.

And that is how it must have looked to Gordon Brown. Megrahi's terminal cancer was good news for everyone but him. It enabled the Scots courts to avoid ruling that Megrahi should never have been convicted. And it allowed the Westminster government to reap the benefits of improved trade while maintaining that the decision was entirely out of its hands.

That's politics for you. But, as in life, things don't always turn out the way you
intended.