Why did the SNP do it?

Looking through correspondence published yesterday, it is clear that Alex Salmond and Kenny MacAskill understood immediately that they would be “left to deal with the consequences” of releasing a convicted mass-murderer. But, after Mr Megrahi had dropped his appeal, and therefore became eligible under the PTA, I can’t comprehend why the Scottish government took it upon itself to release al-Megrahi on compassionate grounds, especially given the identity of the beneficiary of this decision.

The 1998 Scotland Act binds Scotland to all UK treaties. Honouring the UK Libya PTA commitment would not have impinged upon the due processes and jurisdiction of Scots law, and would have shifted the public’s ire onto Mr Salmond’s political enemies: the Labour government. I suspect the answer is that, at the time, the independent minded SNP imagined that a release made according to a PTA wouldn’t grab as many international headlines as one made under the compassionate laws of Scotland.