There appears to be an element that part of the reason we give them aid is not due to Them being anymore needy, but they are strategically placed to help us fight our enemies. We are buying their favour as much as anything.
If that assessment is true, then it is difficult to assess whether we are getting enough bang for our bucks. My guess would be we probably are not.
Cameron's game seems very cynical. He was very anti Pakistan when he was electioneering last May, then done bugg erall about them for the last year. Election time, and he is doubting Pakistan again. Maybe such sabre rattling plays well with a Certain type of Tory voter.