So who is the real power in the land?

It's not politicians or newspaper editors who decide things, but the faceless financiers and arms traders

In the shadows: Truly powerful people reside not in No 10 or the White House but in financial institutions (Jason Alden/bloomberg via Getty)

Simon Raven's novel The Judas Boy (1968) contains a terrific scene in which an historian named Tom Llewellyn, then engaged on a BBC television series, rings up his friend Professor Robert Constable, head of the fictitious Lancaster College, Cambridge, for an intellectual chat. Llewellyn's great interest is the nature of power, and his thesis that, here in the third quarter of the 20th century, power is an increasingly random affair. "It is almost impossible to see it as concentrated in any definite person or persons," he crisply informs the man on the end of the phone, "if only because the world has long since become too complicated for even the most determined and intelligent individual to exert his will, except in very limited areas."

Constable, not immediately convinced by this argument, is brought into line by an illustration from his own professional life. He is the Provost of Lancaster, Llewellyn reminds him, and by definition the most powerful man in the place. On the other hand, his power can never be exercised outright. He can recommend, he can persuade, he can influence, and he can intrigue, but when it comes to doing or acting he cannot dismiss a servant without ratification from a sub-committee. Nonsense, Constable demurs, he can easily get what he wants if he goes about it in the right way. In that case, Llewellyn explains, he is essentially a diplomat, exercising the kind of authority that exists only in so far as the wielder of it is seen.

This exchange leapt back into memory as I began reading some of the publicity attending last week's publication of Power Trip, a book in which Damian McBride, the one-time Downing Street spin doctor, attempts to lift the lid on Rebekah Brooks's allegedly malign influence on public life during Gordon Brown's time as Prime Minister. According to McBride, the former Sun editor was at this point "the most powerful person in Britain", able to throw her metaphorical weight about in such episodes as a campaign to ensure that Paul Stephenson became the Metropolitan Police Commissioner and a government reshuffle in which, against expectation, the Blairite Tessa Jowell kept her post.

McBride also maintains that a Sun journalist told him that Brooks wanted to see the Labour MP Tom Watson "dead" (politically that is – those involved seem to have stopped short of a murder plot) for scheming to force Tony Blair to resign in 2006. It is a bravura exercise, which makes Mrs B sound like a cross between Lucrezia Borgia and Shelob from The Lord of the Rings, and yet, judged by the Raven paradigm, it is hard to imagine that Rupert Murdoch's principal henchwoman was quite the behemoth that McBride represents her to be. She could pull strings, she could utter numberless quiet words in favourably disposed ears, she could make one hell of a fuss on her employer's behalf, but when it came down to it the only direct exercise of authority in which she could engage was to ensure that certain words were printed on pieces of newspaper.

Which, as media historians hasten to assure us, is an enviable form of power, however diminished by falling circulations and the rush to cyberspace. At the same time a glance around public life in 2014 is enough to demonstrate that most of the old sources of direct authority have been emasculated, either by that tantalising abstract democracy, or by the diffusion of power into oligarchy, or merely by way of the administrative complexity by which nearly all contemporary life is waylaid. Certainly, Brooks in her prime was a force to be reckoned with, but did she have as much power as, say, Hugh Cudlipp, the editor of the Daily Mirror in the 1950s, when the paper had a circulation of five million and Labour leaders quaked in their boots when criticised by it?

As for the other authority figures at large in the public sphere, politicians long ago became ciphers. After all, how much real power does David Cameron exercise? He is the first minister of what is supposedly a sovereign state, but unable, owing to our EU membership, to control who passes back and forth across its borders, and uncomfortably aware that much of the military hardware dotted around the nation is owned by one of our allies. He is, additionally, part of a coalition, which severely limits his room for practical manoeuvre, and while he may, more or less, be able to decide who he wants to see around him at the Cabinet table, scarcely any action that he undertakes, from the appointment of the humblest junior minister to the view he takes of President Putin, can be pursued without a series of consultations, diplomatic bunfights and inches given and received.

And so Cameron, like the chief executive of a public company, the senior partner of a Big Four accountancy firm, the vice-chancellor of a university, or the manager of a Premiership football club, is essentially a co-ordinator, esteemed, and occasionally revered, never likely to be ignored by his colleagues or the world at large, but about as capable of genuinely autonomous action as Mr Punch.

Curiously enough, the proof of this long-term retreat from the concept of individual authority can be found in art, and especially literature, where its absence has left a thematic hole that has never been filled. The Victorian novelist, for example, was intensely interested in power, to the point where certain 19th-century novels turn into a causative chain of who owns and can therefore direct the actions of whom. On the other hand, these threads were usually very easy to gather up, a matter of the Queen sitting on her throne, her ministers assembling at Westminster, great landowners administering their estates, and a handful of financiers controlling the money supply.

But the "state of the nation" novel, in which the Victorians excelled, is almost impossible to carry off these days, if only because the sources of power – financial power especially – are so difficult for the non-specialist to locate and, if found, to understand. Even John Lanchester's Capital, for instance, a work by one of the few modern novelists with sufficient knowledge to be able to explain how the modern City of London operates, sometimes reads like a collection of fiscal essays, so esoteric is the information that Lanchester is trying to get across.

Naturally, there are other forms of power – familial, emotional, generational – but the citizens of a supposedly free country with a fine democratic tradition are entitled to know who directs the course of their lives, and whether or not these entities are accountable. It is a cliché, of course, to remark that one of the great drawbacks of a world in which "power" consists of backstairs intrigue and inference, is that it can't be brought to judgement. Simultaneously, you have a suspicion that there are still large numbers of individually powerful people, but that they sit not in No 10 or the White House but in the offices of commodity broking firms and arms traders.

It would be nice if a journalist like Brooks, rather than caballing over the status of some favoured Cabinet minister, could tell us all who they are. We may not be able to do anything about them, or limit their influence, but merely being able to identify them would be a comfort of a sort.