One man has the power to finally destroy the British monarchy.
No, not our best republican thinker Roy Hattersley, nor our best republican rabble-rouser Tony Benn, not even our constitutional moderniser Tony Blair. The man who will finally herald the Republic of Britain is a soon-to-be-21-year-old named William Windsor – or, as the history books might record him, William the Last.
It is time we all admitted three basic facts: William does not want to be king; he hates the idea of being king; he will not be king – ever. When I first suggested this in the New Statesman more than a year ago, professional royal watchers reacted with embarrassed silence. They exist in the comfy world of briefings from the Palace, and they rely on patronage for every strained line of sycophantic copy. Royal correspondents are very reluctant to break the party line and bite the velvet-gloved hand that feeds them, and they know almost nothing about the younger royals. Publicly, then, they scoffed; privately, I suspect, they sweated.
But gradually, since then, they have begun to acknowledge the truth at the heart of this story. Our tabloids lead with revelations about William's pining to escape this country for the United States, his refusal to co-operate with the Palace (and especially not to make his 21st-birthday party into a public event), and his detestation both of the press and of the institution of monarchy. A slew of recent books by royal experts such as Ingrid Seward (editor of Majesty magazine) and Brian Hoey have begun belatedly to hint at this. Yet as a country we have still to absorb the fact that the person who is second-in-line to the throne just ain't going to play the royal game.
But why would William want to renounce the throne, and all the status, luxury and hard cash that comes with it? One anecdote begins to point to his thinking. Nicholas Davies, the royal expert, has revealed that during one holiday in his mid-teens, William was tobogganing down a steep hill in the dark. When he neared the bottom of the slope, where cars were passing, a detective leapt out, seemingly from nowhere. He threw himself on to the sledge and sent William hurtling into a pile of snow. William screamed, "Why do I have to be surrounded by policemen all the time? Why won't you just let me be a normal person?"
It's a good question: why won't we let him be a normal person? Why do we insist on a human sacrifice just so we can cheerfully retain a feudal head of state for us to torment? William's life has at every step been warped and distorted by the sadistic institution of monarchy. Wherever he goes, he is followed by an armed private detective who is at most 50 yards behind.
On his first day at school, there were 150 photographers waiting for him.
His primary school had to have its windows replaced with bullet-proof glass.
He has been threatened with anthrax attacks by terrorist groups.
He had to be driven even from his school to the playing fields in his last year at Eton, in order to avoid the paparazzi.
William's moments of anonymity are so precious that he can list them. In 1999, he was representing his school in a cricket match. The scorer walked up to him in a tea break and brusquely demanded to know his name. He said simply, "William." The scorer snapped, "William who?" When it was explained by the other boys who he was, the scorer was profusely apologetic, but William nearly cried as he said, "Thank you. Thank you! You don't know what that just meant to me."
William has seen the institution of monarchy destroy the lives of his parents.
His father is doomed to wait impatiently for his own mother to die just so he can have a job.
Charles has been forbidden to marry the woman he loves; he was forced to marry a manic-depressive whom he didn't even especially like; and he has been so surrounded by sycophants and deference since birth that his personality is irreparably warped. Yet even his story is a happy one compared to Diana's. On holiday in St Tropez shortly before she died, Diana told reporters that "my boys are urging me to leave the country. They say it's the only way – William is stressed, William gets really freaked out." Famously, William was the one to comfort Diana when she suffered at the hands of the press. He once pushed some tissues under the bathroom door and said, "Don't cry, Mummy."Evidence for this intense hatred of the press litters William's life-story. He chose his university specifically because it was far away from the London media. He rides a motorbike in St Andrews because it makes it much harder to photograph him if he is travelling at speed. In 1997, he asked his parents not to come to his sport's day because the press attention would ruin it for everyone. Even during his 18th-birthday television interview, when he was on his best behaviour, William stressed that he was "uncomfortable" with the press attention. Diana said "he hates the press even more than I did when I first got into this family. He sees them as the enemy."
Yet what is the monarchy now, if not a ceaseless media roadshow, selling nothing but itself?
How can the royal family exist in the public consciousness if not through the flashbulbs and omnipresent cameras? A prince who hates the press is a prince who cannot do his job. "William knows that," a close friend of his told me last year. "That's why he wants to walk away from it now."
Ah, you might be thinking, these are hassles, but he receives a fair bit of compensation for them. Doesn't he get a few palaces, worldwide fame, a fleet of cars and unimaginable luxury? Doesn't that make the job seem a little more appealing? This ignores a basic fact. William could walk away from the monarchy tomorrow and still be a fantastically rich man. He could walk away from the monarchy more easily than any other heir to the throne in history.
William's immense personal fortune is completely unconnected to his royal status – a unique situation.
No matter how rich Charles Windsor appears to be, if he gave up his connections to "the Firm", there would be a huge conflict over whether he owned anything at all. The Duchy of Cornwall, the source of virtually all his income, is owned not by Charles but by whoever happens to be Prince of Wales. If he surrenders the title, he surrenders the wealth. Edward VIII was dependent on his brother's generosity after he abdicated, and had almost no personal funds. William, in contrast, is sitting on a cool £8m inherited from his mother. With this legacy, she achieved one final blow against the Windsor family, even in death.
We live in far too individualistic an age for us to expect one boy, randomly plucked, to sublimate his entire life to the arid concept of "duty". There was a bridging period in the 20th century after the monarchy had lost most of its power, in which the individuals at its head could be induced to sacrifice themselves because, well, everyone was being sacrificed, one way or another.
Elizabeth Windsor could be told that she would have no life because her whole generation had been called upon to give up their lives to combat Hitler's fascism. As she revealed in the documentary Elizabeth R, "It's just a question of maturing into what you're doing and accepting that here you are and that's your fate." But the generation that could yield such stoical, self-sacrificing monarchs is passing into history.
Charles Windsor apparently remains convinced that William's current attitude is just a teenage phase – but William is 20 and has been resolved within his own mind on this issue for four years.
How long can a phase last before it becomes a settled, immutable belief?
Charles has, according to Christopher Andersen (a contributing editor to Time magazine, and thus no tabloid hack) tried to get other people to intervene to persuade William that he must be monarch.
Mark Dyer was William's bodyguard during his gap year, and he was asked to talk William round. They had many long conversations, but William was unwavering and clear: he will never be king.
The psychological pressure that the monarchy has heaped upon William is immense.
In July 1996, when William was 14, he was put on the cover of Time magazine with the headline, "Can This Boy Save The Monarchy?' The answer, surely, is now clear. What will ultimately destroy the monarchy, then, is not republicanism (though that will help). No, it will be the sheer inhumanity of monarchy in a celebrity-obsessed, 24-hour media culture.
Prince William, conscious of the terrible effect this had on his mother, will walk away before the press can argue that, like Diana, he is "asking for it", "thrusting himself into the limelight" or "loving the attention". As it stands, he can make an unimpeachable case that he deserves to be left alone.
Yet time is running out for William to make this decision.
The rapacious tabloids are beginning to demand that he metaphorically shows us a bit more leg.
Annoyed that he does not give more official photo shoots, the Murdoch press has begun to run paparazzi images – in contravention of the agreement made after Diana's death. Speculation about William's girlfriends has begun. In a chilling article in the Daily Mirror earlier this year, its royal correspondent James Whitaker said, "I am not sure what to make of Prince William of Wales. Is he a whingeing wimp because of the way he complains about snappers taking pictures of him every now and again? Or is he a person who needs on-going protection until he decides the time is right to go more high-profile?"
The message is clear: one day, boy, you'll be ours, and there's nothing you can do about it.
So what happens to the monarchy if William quits?
Constitutionally, the throne could easily pass to William's younger brother Harry. But all the evidence suggests Harry is even more wilful, individualistic and ill-inclined to sublimate his energies into a pleasureless life of "duty". The crown could pass to Andrew Windsor. But, really, won't most people conclude that it's time to call it a day?
Of course, there is a precedent in living memory for William's choice. The only voluntary abdication thus far is that of Edward VIII, but the institution survived. Yet William's inclinations demonstrate that if the monarchy continues much longer, it will have to survive wave after wave of abdications.
Even if William is talked round to being king – a scenario that I think is seriously unlikely – will his children be happy to surrender their privacy and their lives? Will their children?
William's abdication would certainly be lethal for the monarchy if he accompanied his resignation with a candid expression of his feelings about the institution.
If he is honest, he will issue a damning public statement making it clear that raising another child in the uniquely cruel goldfish bowl of the British monarchy would be intolerable.
Johann Hari's book 'God Save the Queen? The Truth About the Windsors', is published by Icon Books, £6.99
http://www.independent.co.uk/opinion/commentators/johann-hari/why-william-will-never-be-king-590196.html 
