KEY POINTS:
Two of Italy's greatest cities are suddenly in flux.
In Venice last week, amid great publicity, the sweeping central arc of Santiago Calatrava's new bridge was slotted in between the two steel buttresses at either bank of the Grand Canal: the city's first new bridge in more than seven decades.
Meanwhile, across the country in Florence, a dispute lasting nearly a decade looks like ending in a result: the city fathers have finally given the green light to the first new building project in the city since the boldly modernist railway station in 1935.
The Uffizi Gallery, probably the most famous art museum in the world after the Louvre, is getting a huge new portico, designed by an uncompromising architect of the Japanese avant garde.
Applause anyone? Hip, hip, hurray for the bold Italian town planners? I thought not. That's not why tourists put up with the mess of Italy's airports, its cheating taxi drivers and dismal modern suburbs - to admire modern architecture. We go to Las Vegas or Kuala Lumpur for that.
In Italy, all we ask is for time to stand still. And, until now, the Italians have been happy to oblige.
We look at their town centres, whether a great city like Florence or an Umbrian hill town and think: "God, they know how to do it right. They know how to leave well alone."
How tragic, how embarrassing the contrast with practically anywhere in Britain, repeatedly gutted and hacked and mucked about by generations of misguided planners.
In fact, the changes overtaking Venice and Florence are tiny additions, designed by two of the most lionised architects in the world, requiring the demolition of nothing and merely making these crowded cities slightly more accessible.
Calatrava's bridge may straddle the same waterway as the Rialto but it is at the grungy end of the Grand Canal, where railways and highways and modern concrete mingle with the ancient city.
Yet both projects have detonated furious argument which, in the case of the Uffizi, has gone on for nearly a decade. The new addition to the great museum consists of a flat roof made of steel and polycarbonate, cantilivered out from the museum to form a new exit. That's about all. Yet the project has been greeted by defenders of the city as if it involved the demolition of the museum and its replacement by blocks of flats.
The famous Florentine journalist, Oriana Fallaci, was in the front line - she's the woman who went round the world interviewing the likes of Ayatollah Kohmeini and who beguiled Henry Kissinger into describing (in what he called the most damaging interview he had ever given) power as "the greatest aphrodisiac".
Fallaci called Isozaki's portico "absolutely indecent and unheard of" and threatened to return home from New York and tear it to pieces personally. The under-secretary in the Culture Ministry, Vittorio Sgarbi, called it "this horror", and Isozaki "a kamikaze architect", and did everything in his power to bury the scheme. The film and opera director, Franco Zeffirelli, called it a Japanese conspiracy.
The row made it easier to understand why time appears to have stood still in Italy's towns and cities: the slightest, most exquisitely-calibrated innovation in these places becomes bogged down in years of bitter argument. Nothing gets done.
The last person who built in Italy's old cities was Mussolini, who tore down huge areas of medieval tenements in central Rome and slammed through a great boulevard linking Piazza Venezia with the Colosseum.
None of this would be conceivable today, when to fiddle with the smallest detail of Florence is to invite the heavy artillery of the fogeys. But before we thank heavens for the existence of these diehards, it's as well to see what else they support and oppose.
After the 9/11 attacks on the World Trade Centre - which she witnessed first-hand - Fallaci was reborn as a fiery anti-Islam polemicist, dashing off an incandescent essay, The Rage and the Pride, which became a bestseller across Europe.
For Fallaci, the attacks on the United States meant that Western civilisation was under assault and the great mass of Westerners were by now too decadent and lily-livered to defend it. A portico on the Uffizi was one demonstration of our decline.
Far more menacing was the plan of Florence's Muslims to build themselves a mosque. This was the fall of Constantinople and the siege of Vienna all over again: the horde was back in the saddle.
The Vatican under Benedict XVI has embraced a similar form of messianic paranoia. Although she called herself a "Catholic atheist", Fallaci (who died last year) was granted an audience by the new pope. It must have been a cosy chat, despite the theological divide. Benedict is most unhappy about the omission of a reference to Europe's Christian roots in the draft of the EU constitution. He talks openly about the danger to Western civilisation of the growing number of Muslims in Europe.
To adapt Lampedusa: "Everything must stay the same for everything to stay the same." Trouble is, nothing does. The centre of Florence may be visually unchanged since the time of the Medicis but ask any Florentine and they will tell you that it has changed lamentably during the past 30 years - the old shopkeepers driven out, the whole city made over to serve the tourist trade. Architecture isn't just bricks and mortar, after all.
"Architecture is much more than the way a building looks or the materials used in its construction," as one architectural writer put it recently.
Florence is pickled in aspic - but it changes all the time.
- Independent