‘Unpicking the threads of a three-century-old union would be acrimonious and disruptive for many’This month marks the third year of campaigning for the referendum on Scottish independence which takes place on 18 September. It began as long ago as 7 January 2012, when David Cameron went on the BBC’s  Andrew Marr Show to announce that shortly plans would be unveiled to allow Scottish voters to decide their political future. Within hours, the Scottish National Party’s riposte was to bring it on. The following autumn, London transferred the right to hold a referendum on independence to the SNP Government. Not only could it set the date, but also extend the franchise to those aged between 16 and 18, and decide the wording of the question.An energetic “Yes for