Cameron should be wary of taking the moral high ground in opposition

I’ve just re-read Cameron’s article in the Times and it contains one section that might come back to haunt him, should he become Prime Minister. He writes:

‘Many will be disgusted by the suggestion that ministers in Whitehall encouraged al-Megrahi’s release — and did so for commercial reasons. Diplomacy often involves hard-nosed backroom deals. It would be naive to think otherwise. But there need to be lines you are not prepared to cross; values you will not compromise, whatever deal you broker. I believe even to hint that a convicted terrorist could be used as makeweight for trade is a betrayal of everything that Britain stands for.’ 

I agree with Cameron. That al-Megrahi was released on compassionate grounds is totally irrelevant, it is the principle of including a convicted terrorist in a PTA in return for commercial benefit that is unacceptable. But, as Cameron notes, morally repugnant backroom deals are a staple of diplomacy, especially where securing energy reserves is concerned.