There is a cruel paradox in the career of the man who, in September, will become only the second pope in history to visit Britain. When Cardinal Joseph Ratzinger was elected pope in April 2005, he set about purifying the Catholic Church and returning it to its core values. He also pledged to get his charismatic predecessor, John Paul II, canonised as quickly as possible.
But as a new church scandal exploded last week, hard on the heels of the paedophilia storm, this one involving allegations of massive corruption at the heart of the Roman Curia, Pope Benedict's papal career risks being eclipsed by the dark shadow of John Paul's legacy.
Nobody doubts that the Pope would like the church to be a cleaner, leaner, quieter, purer institution, purged of paedophile priests and greedy careerists; he said as much again last week. But this man, who proposes himself as a new broom and wags his finger at those who take a permissive, typically Italian view of venality, has been at the heart of the church for half a lifetime. All these people are his old colleagues. If this is Sodom, he has been a citizen in good standing for 40 years.
Take the man at the centre of the latest storm, Cardinal Crescenzio Sepe. Aged 67, he was born on the outskirts of Naples and was raised speaking the gritty local dialect, incomprehensible to outsiders. Referred to by Italian newspapers as "l'impresario di Dio", "God's wheeler-dealer", today he is the much-beloved archbishop of the same city: an impressively fat, prosperous looking prelate, who likes nothing better than immersing himself in his crowds of Neapolitan fans, slapping backs and kissing babies. Neapolitans affectionately call their archbishop "O'guapo", local slang for "the boss" – the kindly mafia capo whom people go to with their problems instead of phoning the police. But although no one is accusing him of complicity with the city's fearsome Camorra mafia (Roberto Saviano, author of Gomorrah, a book about the Camorra, leapt to his defence), the crimes of which he is accused are of a type which any mafioso would understand.
Sepe, who is still very young for a cardinal, received spectacular promotions from John Paul II which climaxed when he was given the job of running the church's Jubilee celebrations in 2000. A showman after the late-Pope's heart, he threw a carnival such as Rome has not seen since the days of Nero, and was rewarded for his success with the juicy job of running a church agency called Propaganda Fide, with a Roman property portfolio said to be worth €9bn (£6bn).
Now prosecutors claim that he sold property from that portfolio to a top politician at half its market value in return for his agency receiving special favours from the government. In classic clientelismo style: you scratch the politician's back, and he scratches yours. Except that in this case the alleged perpetrator was one of the most illustrious figures in the Catholic Church.
Pope Benedict, Vatican watchers say, spotted Cardinal Sepe's frailties early on, which is why, in 2006, he unceremoniously removed him from Propaganda Fide – a job that an incumbent would normally expect to hold indefinitely – and packed him off home to Naples.
The cardinal denies that version of what happened as flatly as he denies the corruption charges. Last week he said of the change in his fortunes: "The Holy Father asked me with great insistence to stay in Rome, but my heart was beating for Naples." But apropos of his legal difficulties, he also speaks darkly of enemies "who wanted to strike me, both inside and outside the church".
It is hard to think of two men of God more different than Sepe and Ratzinger: the meaty, glad-handing Mediterranean man of the people, and the ascetic, book-loving Bavarian introvert. In a church regulated according to the Pope's wishes, it's also hard to imagine a man like Sepe obtaining much preferment. But the uncomfortable fact for Benedict is that the two men have one vital thing in common: both of them were chosen and promoted by John Paul II. And it is over his ambiguous legacy that an epic battle is now being fought behind the closed doors of the Vatican.
He may be physically slight, but this Pope is no pushover. Once, when a CNN reporter pursued him with an awkward question, he slapped him on the wrist rather than answer. As John Paul II's "enforcer of the faith" for nearly 30 years, he was ruthless in purging anyone and everyone with whom he disagreed – liberal theologians, those who lobbied the cause of gays in the church, the propounders of liberation theology, and easy-going Catholics who wanted the church to get on closer terms with other faiths. Anyone who he thought was trying to muddy the pure waters of faith with modern ideas was in deep trouble.
Since becoming Pope, he has kept up the hard line, favouring the return of Latin and of priests who turn their back on the congregation during Mass, the end of guitar-strumming populism, and the fashioning of a church that might have fewer members but is purer and less contaminated by the secular world. But Pope Benedict is meeting fierce resistance from within the church, in particular from some senior churchmen like Cardinal Sepe – those most lavishly favoured by John Paul II. Skeletons are tumbling out of the cupboard.
First it was the nightmare of priestly paedophilia: early this year, lawyers acting for US victims of paedophile priests accused Benedict of having been complicit in the cover-up of the crimes, and of having shown no sympathy for the victims. Since then, the Pope has been rowing back hard. En route by air to Lisbon last month he made the announcement that indicated a radical change of tack on the paedophilia crisis. During the flight, he told reporters: "Today the greatest persecution of the church does not come from outside, but from the sin inside the church itself. The church thus has a deep need to relearn penance, to accept purification, to learn on the one hand forgiveness but also the necessity of justice."
He has subsequently reinforced the message and, for the first time, offered humble apologies to the victims. He seems to be winning the public relations battle. But if we believe him to be sincere, he now finds himself in a very difficult situation. He is, according to one Vatican expert, "surrounded by people who share his politics and his conservative theology, but who don't share his views about paedophilia". He will also have to come clean about how his own views have changed. And he has so far shown no sign of being prepared to take either of those steps.
The Pope is a sort of monarch, but his power is severely constrained by the men who were his colleagues when he was still a cardinal. Within the Curia, the church's governing body, Benedict is surrounded by old men like himself who have been together for many decades. All of them, we can assume, have plenty of dirt on all the others.
All these men share broad agreement on the big doctrinal issues facing the church. Arch-conservatives all, like John Paul II, they are united in believing that no concessions should be made to the changing times – no movement on abortion, contraception, stem cells and the other "sanctity of life" issues; nor on the stigma attached to homosexuality, the rules on celibacy or the ban on women priests. They are also united in believing that the church is under siege from the godless compulsions of modern consumer society. The church's enemies, they agree, are without.
But on the question of priestly paedophilia, several are very vulnerable. One of them, Cardinal Angelo Sodano, has been one of the most powerful men in the church for decades. From 1990 to 2006, this fleshy son of a Piedmontese politician was Pope John Paul II's secretary of state, the most important post in the Vatican below the pontiff. Relieved of that job by Benedict he is now, aged 82, dean of the College of Cardinals and still has great power. But he has been tainted by the current scandal. Particularly problematic are his relations with a veritable monster of the modern church, the late Mexican prelate, Marcial Maciel.
Maciel was the founder of a highly conservative order called the Legion of Christ, but it has gradually emerged over the years – particularly since his death in 2008 – that he was much else besides: a morphine addict for decades who sexually abused his own seminarians, fathered several children by two mistresses, and then went on to abuse and rape those children.
Yet Maciel was greatly favoured by John Paul II, remaining persona grata at the Vatican until nearly the end of his life, and Sodano, like other senior members of the Curia (though not Ratzinger) received large cash gifts from him. Sodano repaid Maciel generously by killing a Vatican investigation into his misdeeds in 1998.
Another close ally of Benedict, Cardinal Tarcisio Bertone, the man who replaced Sodano as secretary of state and is much mocked in Vatican circles for his alleged lack of brain- power, has also been badly tarnished by his friendship with Maciel. In 2004, when he was Archbishop of Genoa, he wrote a preface to a book-length interview with Maciel entitled "My Life is Christ", in which he praised "the frankness of one who lives his mission ... with his sights and his heart fixed on Christ Jesus".
Benedict is not tainted in the same way. But although he obtained Maciel's removal from the Legion of Christ in 2006, critics accuse him of featherbedding this dreadful man right to the end. Jason Berry, the American Catholic journalist, who has done most to expose Maciel's crimes over the years, argues that until Benedict sacks Sodano and Bertone, the Maciel shadow will still hang heavy on him.
The problem for the current Pope is that he was there, in the inner circle, throughout the years that Maciel was John Paul II's favourite. And – according to the damaging testimony of a former cardinal – he also went along with the prevailing attitude of his fellow cardinals towards priestly paedophilia in general.
It emerged in April that Cardinal Dario Castrillon Hoyos, a Colombian who for 10 years was in charge of the Vatican department that supervises the clergy, wrote in 2001 with gushing approval to the Bishop of Bayeux, who went to jail rather than give French authorities information about a priest who had raped a minor. "I congratulate you for not turning in a priest to the civil administration," he wrote. "I am delighted to have a colleague ... who ... has preferred prison to turning in his son-priest."
The Vatican confirmed the authenticity of the letter, which had been posted on a French website. But then Castrillon Hoyos himself added a crucial detail. In a radio interview he said the letter was the outcome of a high-level meeting of cardinals at which Ratzinger had been present. "It was a meeting of cardinals," he told RCN radio. "Therefore the current Pope, who at the time was a cardinal, was present."
If the Pope wants to purge paedophilia from the church he must confront the compromised figures within the Curia and dismiss them. But whether that is politically possible is an open question. Sodano, Bertone and friends will fight like tigers to retain their privileges. There is also the question of whether Benedict has the personal, managerial talents to pull it off. When I asked one German expert on the Vatican for his assessment, he merely laughed. "No he doesn't," he said. "He's just a professor!"
When Joseph Ratzinger was elected Pope five years ago, he was seen as a figure who would guarantee continuity after the 26-year reign of the Polish Pope. After all, it was John Paul II who had persuaded Ratzinger to leave his job as Archbishop of Munich and come to Rome to be his chief doctrinal advisor.
With the death of John Paul, the Catholic Church lost its greatest communicator, the man who had travelled more than any pope in history, who inspired eastern Europe's revolt against Communism and enjoyed enormous popularity even among non-Catholics. At his funeral thousands chorused, "Santo subito!" – "Make him a saint immediately!" He is not a saint yet, but he is on the fast track. And, in death, he remains a focus of devotion.
Nobody expected Cardinal Ratzinger to be able to replicate that performance, this introverted, book-loving German with his grand piano, cats and fondness for archaic vestments. But he was seen as the right man to protect Wojtyla's heritage and steer him safely towards sainthood.
Instead the chickens of John Paul's papacy are coming home to roost – the poisonous legacy of Maciel, one of whose brutalised sons spoke about his bizarre and hideous childhood for the first time last week, and all the other paedophile cases that festered during his long reign. And now the alleged venality of Cardinal Sepe has added more pollution to the air.
Both Maciel and Sepe were highly favoured by Pope John Paul II. Their worldliness resonated with the extrovert ex-actor and footballer; for him they brought vitality and energy into the church, not to mention a great deal of money. And he didn't care to look too closely at what else they brought.
Pope Benedict XVI would like the Catholic Church to be very different from the one that ballooned out of all proportion under John Paul, purer, more beautiful, more austere. But far from moulding the church in his own image, he now risks having his own heritage fatally compromised by the sins of the Holy Father. Tasked with fostering John Paul's legacy, he risks being flattened by it.