How gratifying it must be to be one of the senior politicians whom Peter Hennessy regularly invites to sit down with him in a BBC studio and reflect on the patterns of an illustrious career. It is not that a blast of metaphorical trumpets seems to stun the listener’s ear as Hennessy sets about his enquiries, or that a brace of figurative page boys can be imagined leading the subject to his or her chair; merely that Hennessy is so very polite, so very punctilious and so very well informed that even the more loaded questions sound like the choicest compliment.Sir John Major and Lords Hattersley and Steel had been and gone by the time that the former Foreign Secretary and deputy leader of the Labour Party, Dame Margaret Beckett, was wheeled into view (3 September). The product of a lef