Cam's Lockerbie curveball to Salmond

Baltimore, Wednesday afternoon.

On a train bound for New York after what David Cameron must consider a fairly successful Washington leg to his short US tour.

Facing a very difficult start to the day yesterday, with most of the US media and the travelling UK press lobby demanding answers on the Al Megrahi release, Cameron managed to throw what the US baseball commentators call a curveball in the direction of Alex Salmond.

The day should have been all about geo-politics and global economics but the focus was almost entirely on the release of the most notorious prisoner Greenock jail has every held.

At his White House press conference, with the most powerful politician in the world at his side, Cameron managed to de-couple US anger over BP and the Gulf of Mexico oil spill with the release of the Lockerbie bomber.

He did this by making sure he thought BP should carry the can for compensation and clean-up in the Gulf while emphasising that it was not the oil company that freed al Megrahi. That, he said, was the Scottish government in Edinburgh.

By offering a review of all the Whitehall papers relating to the case Cameron offered Obama a way out of calling for a full inquiry, as Hilary Clinton and several US senators still demand.

But with Obama saying the answer was simple: "we need all the facts" the pressure piled on Scottish Justice Secretary Kenny MacAskill to reveal the full evidence that led him to his momentous decision to release al Megrahi. The Scottish government insists it has already published as much as it legally can on the case.

Cameron is holding the inquiry card back, carefully wording his responses to leave the door ajar. Tempting as it might be for the Prime Minister to trash the previous government, and Tony Blair in particular, by ordering an investigation into the “deal in the desert” and all it entailed it would also mean dragging BP through the mud at a time when the company is already on its knees.

And who knows where an inquiry would end. As I said on Newsnight Scotland last night with the Lockerbie conviction we are already in a hall of mirrors. There are many people, including relatives of some of the victims, who do not believe that al Megrahi was the bomber at all.

When I returned to the British ambassador's drinks reception from the BBCs' Washington studios Cameron's people allowed themselves a wry smile when they heard Alex Salmond had been on Newsnight and Newsnight Scotland.

I suppose any evening that ends with Alex Salmond having to rush around TV studios defending his Justice Minister's decision while the PM sips cranberry juice can be considered a domestic success by Downing Street.