When it comes to grand infrastructure projects, Italy rarely seems in a hurry. In the north, a plan to save Venice by means of a gigantic, multi billion-euro flood barrier system has been under discussion for 30 years. In the south, a plan to link Sicily to the Italian mainland by means of a gigantic, multibillion-euro suspension bridge has been under discussion for even longer.
Now, at long last, there is movement in both cases: it appears that the flood barrier system will be built, and the bridge won't. Why that should be so is a tale that offers insights into several aspects of modern Italy - the relationship between the central government in Rome and the outlying regions, the environmentalist movement, organised crime, the shaky public finances, and the contempt in which left and right hold each other.
The two projects were championed by the centre-right government of Silvio Berlusconi, who was prime minister from June 2001 to May 2006. They were the centrepieces of a charac teristically ambitious ?125.8bn (£85.5bn) programme to which Berlusconi committed his government, and which aimed to modernise Italy's crumbling infrastructure. The problem is real: Italy's expenditure on infrastructure, especially road and railway networks, has fallen far behind the western European average over the past 25 years. Yet it was never entirely clear where Berlusconi was going to get the money from. Italy's public debt, which is close to ?1.8trn and the world's third-highest in absolute terms, is larger than the nation's annual economic output. Funds for stupendous public investment schemes are stretched, to say the least.
All this emerged when Romano Prodi's centre-left coalition came to power a month after defeating Berlusconi in last April's general election. Tommaso Padoa-Schioppa, Prodi's finance minister, told Italians that the cost of Berlusconi's projects had boomed to ?173.4bn (£118bn), but that the government had only ?58.4bn (£40bn) available. Hard choices were necessary; some projects would have to be ditched.
One could have been the Venice flood barrier system, otherwise known as Moses (the name conjures up biblical images of the parting of the Red Sea, but stands in Italian, more prosaically, for "experimental electromechanical module"). Massimo Cacciari, the mayor of Venice, disliked Moses. So did Alfonso Pecoraro Scanio, leader of the country's Green Party and Prodi's new environment minister.
Various non-Italian conservation groups, not to mention many ordinary Venetians, were no more enthusiastic about Moses. On 2 February, four members of the European Parliament arrived in Venice to complain that Moses was "disastrous" and had "tremendous economic and environmental costs".
Yet Venice is a wonder of civilisation. Its artistic and architectural treasures are priceless. Some 60,000 people visit it every day. To the rest of the world, Venice defines something quintessentially Italian, even something magnificent and melancholy about mankind in general. It is irreplaceable. Moreover, the city's survival is genuinely threatened. Water levels have slowly gone up since the 1700s and there are even fears that, towards the end of this century, Venice may sink because of the rising Adriatic Sea. Some risks may be linked to global warming, some to the accumulation of silt in the Venetian lagoon, and some to the extraction of methane gas from the nearby sea. Whatever the causes, St Mark's Square, the lowest point in the city, already gets flooded dozens of times a year.
To prevent a catastrophe, Moses envisages the installation of 79 steel barriers, 20 metres wide and up to 28 metres high, that will be fixed to the seabed and rise up to seal Venice's lagoon from the Adriatic when high tides are forecast. If all goes smoothly, the barriers will be operational by 2011 or 2012.
The Prodi government, concluding that action was needed, undertook a brisk review of Moses and announced last November that it would go ahead. The decision was relatively easy to take, in the sense that preliminary work on the barriers had already begun three years earlier.
Yet there were other considerations, too. It helped that, unlike the Sicilian bridge plan, Moses was not tainted by the actual or suspected involvement of the Mafia. Prodi also felt a need to make clear, to environmentalists and to the many irksome local authorities which regularly obstruct central government proposals, that he would not back down on an issue where he deemed the national interest to be at stake.
Finally, although Berlusconi had identified his government with Moses and had personally visited Venice in May 2003 to inaugurate the project, it was never a specifically centre-right initiative. To proceed with Moses gave the lie to the oft-heard accusation from Berlusconi and his supporters that the centre left lacked vision and automatically said "no" to big infrastructure projects. Moses may cost at least ?4.3bn (£3bn), but in the final analysis Prodi's government considers it money well spent.
By contrast, it was clear from the moment of Prodi's election victory that the Sicilian bridge was doomed. Scarcely had Alessandro Bianchi been appointed Prodi's transport minister than he called the bridge "the most useless and damaging project in Italy of the past hundred years".
Such strong language is explained by the bitterness of Italian political rivalries - as well as the inescapable presence of the Mafia in Sicilian life. Berlusconi and the centre right swept Sicily in the 2001 general election, winning all 61 of its parliamentary seats. In last year's election, when Italy switched to a proportional representation system, Berlusconi's coalition thumped Prodi's alliance by 57.9 per cent to 41.9 per cent in Sicily. However, the Italian south as a whole voted for Prodi. What made Sicily different?
According to Antonio Giuffrè, a Cosa Nostra boss who co-operated with Italian prosecutors after his arrest in 2002, the main reason why Berlusconi has done well in Sicilian elections is that the Mafia decided, after the collapse of the locally dominant Christian Democrats in the early 1990s, to throw its weight behind his Forza Italia party. Votes would be traded for favours.
Forza Italia dismisses such allegations as rubbish, and certainly there is no proof of a formal arrangement involving Cosa Nostra. One should also remember that the testimony of Mafia bosses is often self-serving and unreliable. Be that as it may, three facts stand out.
First, Berlusconi and his centre-right allies were the bridge's most passionate supporters. It was during Berlusconi's premiership that the project took a big step forward when an Italian-led consortium won a ?3.88bn (£2.64bn) contract in October 2005 to build it.
Second, Salvatore Cuffaro, president of Sicily's regional government, who is also a big supporter of the bridge, was sent for trial in November 2004 for alleged collusion with the Mafia. Cuffaro, who maintains his innocence, belongs to Berlusconi's centre-right coalition. In spite of his court case, he was re-elected last May.
Last, anti-Mafia investigators in Italy and abroad thwarted an attempt by the Mafia to muscle in on contracts tied to the bridge when, in February 2005, they arrested a construction engineer in Rome and three other people in Canada, France and the UK. The arrests underlined how vulnerable such an expensive public works project is to Mafia penetration.
There were other dangers as well. The Strait of Messina, which separates Reggio Calabria on the Italian mainland from the Sicilian town of Messina, is where Homer imagined Odysseus and his men sailing between the monstrous duo of Scylla and Charybdis. It is an earthquake-prone area where a tremor killed between 80,000 and 100,000 people in 1908.
Stretto di Messina, the Italian company running the project, says that the bridge, which would have a central span of 3.3 kilometres, making it the world's longest suspension bridge, could withstand a quake of 7.1 on the Richter scale - a threshold roughly as high as the 1908 tremor. Not all geologists are convinced, however. Some fret that the bridge would not, in any case, survive Sicily's slow but irreversible drift away from the mainland.
A final argument against building the bridge was that it would not be used enough to be profitable. Designers thought it should be able to handle 6,000 vehicles an hour and 200 trains a day; at present, about 9,000 vehicles cross the strait by ferry every day. Many businessmen and travellers hate the journey, partly because of long ferry queues but also because of poor road and rail connections from Messina to the rest of Sicily, and from Reggio Calabria to other parts of the Italian south. It is these connections that need substantial investment; the bridge, if ever it is to be built, can come later.
So, at least, argued the Prodi government as it slammed the door shut on the bridge project. The centre right was outraged. "It took us five years to put this together, and it took the left five minutes to destroy it," Berlusconi complained earlier this month.
However, not for the first time, Prodi may have been more in tune with the public. The Sicilian regional government launched an online poll last month to see if people wanted the bridge. It confidently expected the answer to be "yes", but in the first few days of voting, 55 per cent said "no".
So there it is: Venice gets its flood barriers, Sicily doesn't get its bridge. But only a rash person predicts anything with confidence in Italy. Prodi's government is hanging by a thread, with the narrowest of parliamentary majorities. If he falls, Berlusconi, and Sicily's bridge, could make a comeback. Equally, opposition to the Venice flood barriers could resurface.
In the end, this is the fascination, and frustration, of Italy. Arguing about something is refined into an art form. As for taking a final decision - why, that just spoils the fun.
Tony Barber is Rome correspondent of the FT