“When the Eye of Sauron is off the Whitehall machine, things stop working,” The Sun was told last week by a senior Downing Street figure.  Whoever this person may be, he certainly knows his onions.  And his Tolkien.

Like many metaphors, it works on different levels.  At one, the Eye is an expression of the will of Sauron, the demonic villain of the tale, to pin down places and people before devouring them.  At another, it is a symbol of the mangled bureaucracy of dysfunctional states.  Or armies.  There may be an echo of the military headquarters and staff officers of the First World War, in which Tolkien served.

“The Eye was busy elsewhere,” one character tells another, at a point in the story.  “They couldn’t get Lugbúrz to pay attention for a good while, I’m told.”  “Lugbúrz” is Sauron’s command and control centre.  Gollum puts it most plainly: “His Eye is all round, but it attends more to some places than to others. He can’t see everything all at once, not yet.”

As that Downing Street figure spotted, it is also a brilliant symbol of how modern British government works.

Number Ten has got bigger, in relation to the rest of Whitehall, over the past 20 years.  Tony Blair began the trend in earnest: introducing a new Delivery Unit to keep departments up to speed; giving Alastair Campbell the power to instruct civil servants, bringing in more fixers and operators to Downing Street.

If the core of government is like Sauron’s Eye, this is one that was gazing further afield.

The tendency has waxed and waned.  David Cameron abolished the unit, only later to re-form it.  The powers of the centre reached a terrifying climax under Theresa May Mark One, as this site calls it, when Nick Timothy and Fiona Hill dominated Number Ten.

They were Lugbúrz on steroids, as it were.

The power of the centre shrivelled under May Mark Two, as her majority and authority dwindled to nothing.  Under Johnson and his landslide, it is back with a vengeance – sometimes literally.  The bloody head of Julian Smith, currently pronged on a spike above the door to Number Ten, is evidence of Johnson’s long memory, his capacity to nurse a grudge and, later, deliver his revenge cold.

He has a sunnier side.  But it may not be for nothing that he has described his favourite film scene as “the multiple retribution killings at the end” of The Godfather.  Amidst these tensions, Dominic Cummings is a useful agent.  He is hugely influential…and ultimately dispensable.  If the wrong adviser is appointed, or the BBC is over-briefed against, the Prime Minister can distance himself from his ruthless SpAd – just as he does this morning.

Cummings fulfils the lightning-rod function legendarily reserved for the Tsar’s evil counsellors.  The cry goes up: “If only Stalin knew!”

Yes, the current Eye in Downing Street is Johnson’s, not Cummings’.  But, like the officialdom of the Great War, the more it strains, the less it sees.  It becomes “blind almost to all else that is moving”.

To be sure, modern government needs a strong centre.  And the growth in the Eye’s ambitions, over the last 20 years or so, is a response to changing landscape.  Government is busier than ever.  There is more moving out there to keep a watch on.

So it is tempting, for example, to merge Numbers 10 and 11 – at the top, anyway.  To make the Eye see further, faster.  To fix on problems and sort them quicker.  Hence the decision to get Johnson and Rishi Sunak’s top teams working together.

Such accumulating centrism sits oddly with the dominant fashion for devolution, elected mayors, police commissioners, local enterprise partnerships, and the rest of the alphabet soup of English local government.  Downing Street would say that there’s no contradiction, and maybe it’s right.

Certainly, the Eye has limited use for potential rivals.  Cabinet Ministers have usually been chosen partly because they will be effective in the Commons and on the media.  This Government still needs some people at the top table of that type: Michael Gove, Brandon Lewis, Sunak himself.

But the sum of the reshuffle suggests that Number Ten thinks that they are less important than before.  And that what matters more is competence, loyalty and discipline – i.e: not showboating in the media.  If the papers and TV are losing out to YouTube and Facebook, why bother with those awkward interviews on The Today Programme or Newsnight when you can reach voters directly?  Why worry about Andrew Neil?

If what happens on the floor of the Commons is less testing, because Oliver Letwin and Dominic Grieve and David Gauke and others have gone, does being deft at the despatch box really matter so much?  We believe that it does.  But understand why the Prime Minister, Cummings and others might think that they have their opponents where they want them, at least for a while.

So Beware the Eye of Johnson.  Nonetheless, it is worth remembering the end of Tolkien’s story, as power accumulates at the centre, Ministers shrink in size, the Andrew Sabiskys of this world can swiftly be dispensed with, and the BBC may or may not be overhauled (which should and must happen).  The Eye couldn’t see everywhere. Two small opponents slipped beneath the radar, and finished it off a stroke.