What a site: trouble at the World Trade Centre

There was one requirement, significant and barely questioned, which was that skyscrapers should be put back on the site. This was despite the fact this was not an area in which there was a compelling commercial case for building very tall towers. The old Twin Towers had not commanded the highest rents, and it had been a struggle to fill them. This requirement also glossed over the obvious and still-unanswered question: would anyone want to work in towers that would clearly be on the top of al Qaeda's hit-list? Would you? Could you sit at your desk and not flinch each time you saw a plane?

There might have been a case for a more subtle response. To have created a new district of New York, perhaps, with the rich, humane and diverse intricacy of people and activities at which that city excels, a piece of urban civilisation to answer the crude brutalities of the terrorists. But in 2002, with George W Bush high in the polls and the country still feeling a huge sense of national hurt, there was little chance of subtlety. The mood, which also brought the invasion of Iraq, was for a demonstration of might. George Pataki, governor of New York until 2006, would call the tower idea 'a symbol of our freedom and independence'.

The competition was run by the Lower Manhattan Development Corporation, the public agency charged with regenerating the area. The winner was Daniel Libeskind, the son of Polish-Jewish holocaust survivors who made his name as an academic and theorist before realising, as his first ever building project, the acclaimed Jewish Museum in Berlin. He pushed the right buttons. He appeared on Oprah, spoke of his arrival in Manhattan as a young migrant, and wore cowboy boots.

Although plainly of a liberalintellectual-Democrat bent, he happily adopted Bush's use of language in the wake of 9/11: 'freedom' to mean 'America' and 'heroes' to mean 'victims'.

(Right) From left: Santiago Calavatra in 2009 with his model for the station

Libeskind proposed a spiralling arrangement of towers ascending to the pointed, offcentre pinnacle of the Freedom Tower, whose profile would echo that of the Statue of Liberty. He assigned it the height of 1,776 feet, to recall the year of the Declaration of Independence. Unfortunately, however, his was a victory as symbolic as his design. Silverstein's contract with the Port Authority entitled him to employ whichever architect he wanted, and he wanted someone with a stronger record in commercial buildings than Libeskind.

Silverstein wanted the giant multinational practice of Skidmore, Owings & Merrill (SOM), and its partner David Childs. Born in 1941, Childs had produced a series of competent office buildings, including Westferry Circus at Canary Wharf and airport buildings in Toronto and Tel Aviv.

For a while the owlish, suited Childs and the black-clad Libeskind worked together, but it was clear who was calling the shots. The two started feuding, and then called in lawyers. When the smoke cleared, Childs was in possession of the battlefield. Libeskind later claimed that: 'There was never disappointment. What I learned is that you have to work with everybody and come to a compromise. Even if you don't want to work with those people, even if you think they are subverting your vision. There are always struggles to build a piece of a city.' But the fact is that Childs developed a plan that contained only the merest nods to Libeskind's ideas, such as the 1,776-foot height and the location of the Freedom Tower. The spiral became a more rigid line-up of four towers, in ascending height order, without the dynamic sweep of Libeskind's plan.

The Freedom Tower became a symmetrical monolith, of the kind that SOM has been turning out for 50 years, without the off-centre twist. Childs said that 'the pure simplicity of this building will be seen as the proper symbol for the memorial', but it was less Lady Liberty, more an investment banker in a suit.

The Tower, its design modified after objections from the police about its vulnerability to terrorism, had elaborate safety precautions. It would have extra-wide escape stairs and a hefty concrete base to protect against truck bombs, sheathed in shatterproof glass. It would be set back from the street, also to protect against truck bombs. The effect, argued critics, was to create a 'Fear Tower'. 'It speaks less of resilience and tolerance than of paranoia,' wrote the architecture critic of The New York Times. 'It's a building armoured against an outside world that we no longer trust.'

The three further towers were then designed by the British architects Lords Foster and Rogers, and the Japanese architect Fumihiko Maki. All three are winners of architecture's most prestigious award, the Pritzker Prize. Rogers, 75, and Foster, 74, are the most famous British architects of their or most generations, while the more reticent and professorial Maki, 80, is highly respected.

The relative heights of all four towers reflected the relative status of the architects designing them, as seen from Manhattan: SOM, the local practice, being the tallest and most important; followed by Foster; then Rogers; then Maki. Each has its stylistic tics, and refers not at all to its neighbour.

(Above) Current designs for the site by (from left) Childs, Foster, Rogers and Maki

The towers, if they are all built, will stand over a tree-covered space containing the National September 11 Memorial & Museum, designed by Michael Arad, son of an Israeli diplomat who, as a previously unknown architect, beat 5,200 others in the 2004 competition for the project. Arad, now 40, proposed pools of water set 30 feet deep in the square outlines of the sites where the twin towers once stood, with water cascading down their sides.

This project has also attracted controversy. Early price estimates put it at an astounding $1 billion, including its associated museum, while some victims' relatives objected to its being below ground. Galleries that would have carried the names of the dead were taken out, as a cost-saving measure. The budget was reduced to $510 million, but according to some reports is now heading upwards again. London's 7/7 memorial, an array of 52 stainless steel pillars (each representing one of the victims killed) by the young practice of Carmody Groarke, by contrast, will open next month in Hyde Park, four years after the bombings, and at roughly one 500th of the cost.

On another part of the site, nestling between the Foster and Rogers towers, would be the extravagant, porcupineshaped roof of the new $3.2 billion transport interchange which, it is hoped, will raise the desirability of the area. The roof is designed by Santiago Calatrava, the Zurich-based architect/engineer who is often brought in to introduce glamour to public projects, such as the Olympic stadium in Athens, and the astounding winged roof of the Milwaukee Art Museum.

Under these plans the World Trade Center site will become a collection of glittering objects - four towers, the memorial, the interchange - that bear little relationship to each other. The plan reflects the increasingly unfashionable idea that the way to get good architecture is simply to hire good architects. Here, some of the biggest names in the world are each allowed to do their own thing. Foster is crystalline, Calatrava spiky, Rogers filigree, SOM sleek. It is a Babel of egos, whose incoherence reflects the weak and divided leadership of the site. And even achieving this plan now looks doubtful. The estate agents Cushman & Wakefield, commissioned by the Port Authority, recently predicted that One World Trade Center would not be fully occupied until 2019, and the Rogers tower not until the very distant date of 2037. From the perspective of a commercial developer, this is as good as saying never.

The $3 billion One World Trade Center is going up only because the Port Authority, a public body, is paying for it. There is little sign of enthusiasm from businesses for occupying it, and it is likely that hapless employees of governmental institutions will be shuffled into this glittering ninepin, to avoid the embarrassment of it being empty. The Foster and Rogers towers, which Foster had hailed as 'the renaissance of the New York skyline', face the sane but humiliating decision to reduce them to stubs. They will resemble the miniature Stonehenge produced when Spinal Tap's set designers confused inches with feet.

Rogers and Foster do not now comment on the subject, referring inquiries to Silverstein Properties. The latter still want the Rogers and Foster towers built, but they lack the will and/or means to pay for it themselves. They want the Port Authority to 'backstop' the financing, which would mean the Authority would carry some of the risk if Cushman & Wakefield's gloomy predictions turn out to be correct. They are upbeat about the desirability of the area, and say that 'New York will bounce back strongly over the next five years while we are building these buildings... Nobody at Silverstein is ever going to give up on New York'. They cite the fact that a neighbouring building is 85 per cent let three years after its completion. This is not wholly compelling evidence for their case.

For its part, the Port Authority, which is already investing billions in the transport interchange and the main tower, is reluctant to pump more into the site. This month and last, Mayor Bloomberg has invited Silverstein and the Port Authority into Gracie Mansion, his official residence, in an attempt to bang their heads together and make some progress. 'We want to create a roadmap that would create progress at the site,' said Bloomberg, but no news has yet emerged as to how he is doing.

In the end the current state of Ground Zero is a classic example of what happens when symbolic aspirations and commercial practicalities collide, and when political grandstanding gets in the way of common sense. It will not be all bad - Arad's memorial will eventually provide a fitting place for remembrance, and the transport interchange will be an asset for Lower Manhattan - but the botched development around them will be a poor return for the hope and huge sums, perhaps $12 billion in all, invested in it.