AFTER BATHING in the warm, fuzzy glow of the Mandela years, South Africans today are deeply demoralised people. The lights are going out in homes, mines, factories and shopping malls as the national power authority, Eskom - suffering from mismanagement, lack of foresight, a failure to maintain power stations and a flight of skilled engineers to other countries - implements rolling power cuts that plunge towns and cities into daily chaos.

Major industrial projects are on hold. The only healthy enterprise now worth being involved in is the sale of small diesel generators to powerless households but even this business has run out of supplies and spare parts from China.

The currency, the rand, has entered freefall. Crime, much of it gratuitously violent, is rampant, and the national police chief faces trial for corruption and defeating the ends of justice as a result of his alleged deals with a local mafia kingpin and dealer in hard drugs.

Newly elected African National Congress (ANC) leader Jacob Zuma, the state president-in-waiting, narrowly escaped being jailed for raping an HIV-positive woman last year, and faces trial later this year for soliciting and accepting bribes in connection with South Africa's shady multi-billion-pound arms deal with British, German and French weapons manufacturers.

One local newspaper columnist suggests that Zuma has done for South Africa's international image what Borat has done for Kazakhstan. ANC leaders in 2008 still speak in the spiritually dead jargon they learned in exile in pre-1989 Moscow, East Berlin and Sofia while promiscuously embracing capitalist icons - Mercedes 4x4s, Hugo Boss suits, Bruno Magli shoes and Louis Vuitton bags which they swing, packed with money passed to them under countless tables - as they wing their way to their houses in the south of France.

It all adds up to a hydra-headed crisis of huge proportions - a perfect storm as the Rainbow Nation slides off the end of the rainbow and descends in the direction of the massed ranks of failed African states. Eskom has warned foreign investors with millions to sink into big industrial and mining projects: we don't want you here until at least 2013, when new power stations will be built.

In the first month of this year, the rand fell 12% against the world's major currencies and foreign investors sold off more than £600 million worth of South African stocks, the biggest sell-off for more than seven years.

"There will be further outflows this month, because there won't be any news that will convince investors the local growth picture is going to change for the better," said Rudi van der Merwe, a fund manager at South Africa's Standard Bank.

Commenting on the massive power cuts, Trevor Gaunt, professor of electrical engineering at the University of Cape Town, who warned the government eight years ago of the impending crisis, said: "The damage is huge, and now South Africa looks just like the rest of Africa. Maybe it will take 20 years to recover."

The power cuts have hit the country's platinum, gold, manganese and high-quality export coal mines particularly hard, with no production on some days and only 40% to 60% on others.

"The shutdown of the mining industry is an extraordinary, unprecedented event," said Anton Eberhard, a leading energy expert and professor of business studies at the University of Cape Town.

"That's a powerful message, massively damaging to South Africa's reputation for new investment. Our country was built on the mines."

To examine how the country, widely hailed as Africa's last best chance, arrived at this parlous state, the particular troubles engulfing the Scorpions (the popular name of the National Prosecuting Authority) offers a useful starting point.

The elite unit, modelled on America's FBI and operating in close co-operation with Britain's Serious Fraud Office (SFO), is one of the big successes of post-apartheid South Africa. An independent institution, separate from the slipshod South African Police Service, the Scorpions enjoy massive public support.

The unit's edict is to focus on people "who commit and profit from organised crime", and it has been hugely successful in carrying out its mandate. It has pursued and pinned down thousands of high-profile and complex networks of national and international corporate and public fraudsters.

Drug kingpins, smugglers and racketeers have felt the Scorpions' sting. A major gang that smuggle platinum, South Africa's biggest foreign exchange earner, to a corrupt English smelting plant has been bust as the result of a huge joint operation between the SFO and the Scorpions. But the Scorpions, whose top men were trained by Scotland Yard, have been too successful for their own good.

The ANC government never anticipated the crack crimebusters would take their constitutional independence seriously and investigate the top ranks of the former liberation movement itself.

The Scorpions have probed into, and successfully prosecuted, ANC MPs who falsified their parliamentary expenses. They secured a jail sentence for the ANC's chief whip, who took bribes from the German weapons manufacturer that sold frigates and submarines to the South African Defence Force. They sent to jail for 15 years a businessman who paid hundreds of bribes to then state vice-president Jacob Zuma in connection with the arms deal. Zuma was found by the judge to have a corrupt relationship with the businessman, and now the Scorpions have charged Zuma himself with fraud, corruption, tax evasion, racketeering and defeating the ends of justice. His trial will begin in August.

The Scorpions last month charged Jackie Selebi, the national police chief, a close friend of state president Thabo Mbeki, with corruption and defeating the ends of justice. Commissioner Selebi, who infamously called a white police sergeant a "f***ing chimpanzee" when she failed to recognise him during an unannounced visit to her Pretoria station, has stepped down pending his trial.

But now both wings of the venomously divided ANC - ANC-Mbeki and ANC-Zuma - want the Scorpions crushed, ideally by June this year. The message this will send to the outside world is that South Africa's rulers want only certain categories of crime investigated, while leaving government ministers and other politicians free to stuff their already heavily lined pockets.

No good reason for emasculating the Scorpions has been put forward. "That's because there isn't one," said Peter Bruce, editor of the influential Business Day, South Africa's equivalent of, and part-owned by, The Financial Times, in his weekly column.

"The Scorpions are being killed off because they investigate too much corruption that involves ANC leaders. It is as simple and ugly as that," he added.

The demise of the Scorpions can only exacerbate South Africa's out-of-control crime situation, ranked for its scale and violence only behind Colombia. Everyone has friends and acquaintances who have had guns held to their heads by gangsters, who also blow up ATM machines and hijack security trucks, sawing off their roofs to get at the cash.

In the past few days my next-door neighbour, John Matshikiza, a distinguished actor who trained at the Royal Shakespeare Company and is the son of the composer of the South African musical King Kong, had been violently attacked, and friends visiting from Zimbabwe had their car stolen outside my front window in broad daylight.

My friends flew home to Zimbabwe without their car and the tinned food supplies they had bought to help withstand their country's dire political and food crisis and 27,000% inflation. Matshikiza, a former member of the Glasgow Citizens Theatre company, was held up by three gunmen as he drove his car into his garage late at night. He gave them his car keys, wallet, cellphone and luxury watch and begged them not to harm his partner, who was inside the house.

As one gunman drove the car away, the other two beat Matshikiza unconscious with broken bottles, and now his head is so comprehensively stitched that it looks like a map of the London Underground.

These assaults were personal, but mild compared with much commonplace crime.

Last week, for example, 18-year-old Razelle Botha, who passed all her A-levels with marks of more than 90% and was about to train as a doctor, returned home with her father, Professor Willem Botha, founder of the geophysics department at the University of Pretoria, from buying pizzas for the family. Inside the house, armed gunmen confronted them. They shot Professor Botha in the leg and pumped bullets into Razelle.

One severed her spine. Now she is fighting for her life and will never walk again, and may never become a doctor. The gunmen stole a laptop computer and a camera.

Feeding the perfect storm are the two centres of ANC power in the country at the moment. On the one hand, there is the ANC in parliament, led by President Mbeki, who last Friday gave a state-of-the-nation address and apologised to the country for the power crisis.

Mbeki made only the briefest of mentions of the national Aids crisis, with more than six million people HIV-positive. He did not address the Scorpions crisis. The collapsing public hospital system, under his eccentric health minister Manto Tshabalala-Msimang, an alcoholic who recently jumped the public queue for a liver transplant, received no attention. And the name Jacob Zuma did not pass his lips.

Last December Mbeki and Zuma stood against each other for the leadership of the ANC at the party's five-yearly electoral congress. Mbeki, who cannot stand again as state president beyond next year's parliamentary and presidential elections, hoped to remain the power behind the throne of a new state president of his choosing.

Zuma, a Zulu populist with some 20 children by various wives and mistresses, hoped to prove that last year's rape case, and the trial he faces this year for corruption and other charges, were part of a plot by Mbeki to use state institutions to discredit him. Mbeki assumed that the notion of Zuma assuming next year the mantle worn by Nelson Mandela as South Africa's first black state president would be so appalling to delegates, a deeply sad and precipitous decline, that his own re-election as ANC leader was a shoo-in.

But Mbeki completely miscalculated his own unpopularity - his perceived arrogance, failure to solve health and crime problems, his failure to deliver to the poor - and he lost. Now Zuma insists that he is the leader of the country and ANC MPs in parliament must take its orders from him, while Mbeki soldiers on until next year as state president, ordering MPs to toe his line.

Greatly understated, it is a mess. Its scale will be dramatically illustrated if South Africa's hosting of the 2010 World Cup is withdrawn by Fifa, the world football body.

Already South African premier league football evening games are being played after midnight because power for floodlights cannot be guaranteed before that time. Justice Malala, one of the country's top newspaper columnists, has called on Fifa to end the agony quickly.

"I don't want South Africa to host the football World Cup because there is no culture of responsibility in this country," he wrote in Johannesburg's bestselling Sunday Times.

"The most outrageous behaviour and incompetence is glossed over. No-one is fired. I have had enough of this nonsense, of keeping quiet and ignoring the fact that the train is about to run us over.

"It is increasingly clear that our leaders are incapable of making a success of it. Scrap the thing and give it to Australia, Germany or whoever will spare us the ignominy of watching things fall apart here - football tourists being held up and shot, the lights going out, while our politicians tell us everything is all right."