Night-time haunts go in and out of fashion, but the Bar Basso in Milan, which opened in 1967, remains one of the city’s most venerable social institutions. Embodying a very Milanese combination of stylish prosperity and tasteful design, it is a favourite destination for the area’s creative elite and the discreetly wealthy.

Tucked away in a corner, Pierluigi Dialuce is explaining why, if a political nightmare unfolds in the rest of Italy, the city he has made his home will be able to cope.

“It’s very possible that the country is heading for a moment when the hard right and Matteo Salvini take power,” he says, “Perhaps in an alliance with the Brothers of Italy party. We’re talking Viktor Orbán-style politics at that point. But Milan will stay as it is. There’s too much money here for that not to be the case. And then we will be even more different from the rest of Italy. But that’s fine by me. Better that way, in fact.”

Dialuce is a thirtysomething financial consultant with one of the myriad multinational organisations that have made Milan a service hub for international capital. He grew up in Rome, but came north 13 years ago to read economics at the famous Bocconi University. For a while he worked for Barclays bank and then had a few brief spells abroad. Now he intends to stay in Italy’s richest, most cosmopolitan city.

“This place has changed enormously in recent years. It’s much more international,” he says. “There’s been so much investment and there’s so much culture going on. Stuff that you won’t find in the rest of Italy. The ‘Milanese’ don’t exist anymore. Milan is made up of the professionals who have come here because there are opportunities that don’t exist back home. They’re the best of Italy. It’s a kind of natural selection that goes on, creating a community which is much more European, open and tolerant in its mindset. Milan is not Italy.”

Dialuce’s confidence is borne out by a poll carried out last year which found that 85% of residents would not wish to live anywhere else, while 81% believed that their city should be seen as an economic role model to emulate. But while the likes of Paris, Amsterdam, Munich and Berlin might reasonably aspire to compete with Milan, the rest of Italy, after 20 years of economic stagnation, can only dream.

Facebook Twitter Pinterest One of Milan’s modern residential districts. Photograph: Alamy

Milan now moves in its own orbit, reaping rich rewards from an economy centred on finance, tech, design and innovation. It’s become fashionable as well as rich. In 2020, the city will host the World Cities Culture Summit. In 2026, the Winter Olympics will be based here, shared with the Alpine town of Cortina. Unprecedented levels of foreign investment are driving new developments across the city. Over 40 major construction projects worth $21bn will be undertaken over the next 15 years. The left-of-centre mayor, Giuseppe Sala, has presided over a 50% rise in tourism based on aggressive promotion of the city’s cultural assets, from the paintings of Leonardo da Vinci to the attractions of the city’s thriving LGBT quarter in Porta Venezia.

Only the city’s two football teams, Internazionale and AC Milan, have failed to keep up with the city’s pace of growth and development, though Inter, now under Chinese ownership, lie a respectable second in the national championship. And the more the money flows in, the more ambitious and talented young Italians arrive, and the more foreign investors bet on the future. Across the city monuments to prosperity have sprung up such as Zaha Hadid’s “twisting tower”, which overlooks a park and gated communities of luxury condominiums designed by Hadid, Daniel Libeskind and the Japanese architect Arata Isozaki. Welcome to Milan, a truly global city. But, as elsewhere in Europe, this metropolitan success story is coming at a high price.

Last May the Centre for European Reform, a Brussels-based thinktank, published a paper entitled The Big European Sort? The diverging fortunes of Europe’s regions. The “sort” refers to a sifting process that is steadily transforming the demography of EU member states, and driving the polarisation that increasingly defines politics in Europe and beyond.

The post-industrial city, say the study’s authors, is a success story based on the clustering of high-end services in the great metropolises. “In the 1980s and 90s,” they write, “industrial heartlands such as the Ruhr in Germany suffered from relative – and in some cases absolute – decline in industrial output. The largest cities – often capitals such as Paris or London – were able to replace a declining industrial production with high-value services.”

By the 21st century, these reinvented metropolises needed a new kind of population, which was “younger, more highly educated and richer than Europeans who live in less successful cities and towns,” the report says. “Less successful places are losing people, especially in countries with ageing demographics.”

The consequence, the report concludes, is a damaging divide between ageing towns and rural areas and the great cities. “The political effects of regional sorting are predictable: frustration at relative economic decline in poorer regions, a sense of loss of community as younger people leave, and grievance about metropolitan ‘elites’ running the country for their own benefit.”

Facebook Twitter Pinterest Across Europe, less successful towns with ageing demographics are in decline. Photograph: Christopher Thomond/The Guardian

These themes have also preoccupied thinkers such as Christophe Guilluy and Guillaume Faburel in France. Both are geographers, reflecting the new reality that the politics of place is becoming as important as class, race and gender in understanding the signs of turbulent times.

Guilluy, the author of La France périphérique, is a trenchant critic of what he describes as 21st century “citadels”, which have become the “shop window of happy globalisation”. Superstar cities, he argues, are the preserve of an inner-city elite, whose everyday needs are catered for by a low-paid precariat, living on the peripheries of the urban sprawl. “The traditional working classes no longer live where the good jobs and wealth are created,” says Guilluy.

Having grown up in Milan, Prof Roberto Camagni has watched it boom in recent years with a mixture of admiration and trepidation. Camagni is a professor of urban economics at the Politecnico di Milano. “I thought it would peak, but it keeps on going,” he says. He has calculated that between 2000 and 2016, Milan increased its share of Italy’s gross domestic product by an astonishing 17.7%. Only four other cities registered increases, and the next highest was Rome at 4.4%. Everywhere else lost out as the country’s economy flatlined.

“It was big cities like Milan, not nation states, which benefited most from the great wave of integration that came with the European single market,” Camagni says.

“The city provides financiers, lawyers, designers, artists, culture, everything required to be a modern international hub. It has a monopoly on the high-end services that command the highest prices, and the rest of Italy has to pay those prices. In fashion it sits on top of a long global chain that has low-paid garment workers in Vietnam at the bottom. The problem is that this miracle in Milan only really involves the million or so people at its very heart. The city has shaken off the industrial hinterland that made it great in the 20th century. In the end this creates a problem of dignity for other places.”

Places like Melzo, for example. The small Lombard town lies about 12 miles north-west of Milan and no more than 20 minutes away on the train. Leaving the station, travellers are confronted by a stretch of wasteland and a huge, crumbling monument to a distinguished past, when Melzo’s dairy industry enjoyed national fame. This melancholy edifice is what remains of the famous old Galbani offices, the HQ of the firm producing the original Bel Paese cheese at the beginning of the 20th century. Abandoned in the mid-80s, it has, say locals, become a public health hazard. The industrial ruins serve to underline the sense of a loss of vocation in a proud town, where the metalworking industry has also disappeared. In the summer metalworkers from Melzo were among thousands of demonstrators in Milan, protesting against the possible loss of 2,000 steelworking jobs in Lombardy. Deindustrialisation has turned Melzo into a dormitory town.

Antony Bottani works as a lab technician for a firm producing chemical products 15 miles away. Now on the verge of retirement, he was born and grew up in Melzo. “The town has lost a lot of its life,” he says sadly. “Big firms like Galbani were powering ahead here and the town thrived. That’s all gone and much of the countryside around here is now used for agri-tourism, not farming, so there aren’t the jobs on the land. And the town is getting older and older.”

Facebook Twitter Pinterest Outside of Italy’s more liberal cities, voters in towns and rural areas are turning to Matteo Salvini’s right-wing Lega party. Photograph: Antonio Masiello/Getty Images

Bottani’s son Gabriele is 18 and goes to college in the nearby town of Gorgonzola. “He’s studying IT,” he says. “Hopefully that way he’ll find work in Milan. But it’s not good the way that towns like Melzo are going. This used to be a Communist town in the old days. Now it’s become a town of the right. People want change. They’re pissed off.”

In last May’s European elections Milan voted for the Democratic party. The rest of Lombardy voted for Salvini’s League. Afterwards Pietro Bussolati, a Milanese Democratic party official on Lombardy’s regional council, sat down with colleagues and drew up a novel map of metropolitan Milan. “It wasn’t just of the city,” he explains, “but also of the surrounding area. What we found was that the proportion of centre-left votes in a place was directly related to the availability of fast means of transport to Milan itself. In all the places where people didn’t have that, and frequent contact with Milan was more difficult, the vote went to the centre-right.

“In my opinion this is not about salaries; it’s about how much direct knowledge one has of how innovation and openness help bring about economic growth. The more you can see that the universities, the research institutes and openness to the rest of the world bring about opportunities you wouldn’t otherwise have, the more you are likely to vote centre-left and express liberal values. And by the same token, the less you see of that, the more likely you are to fall for myths about migrants who steal and so on, and vote for the League.”

Nevertheless, Bussolati is realistic enough to concede that better transport links will not truly bridge the yawning economic and cultural divide between Europe’s flourishing mega-cities and angry towns. “There is no rabbit to pull out of the hat which can solve a problem which has been developing for years,” he says.

“The future is going to be less and less about nation states and more and more about the great cities. They have the wealth of the future in their hands. The goal has to be to make sure that wealth doesn’t just stay in those cities but is dispersed outside the city gates. This is the massive priority for the global left: how to manage the future growth of the great cities.”

The new CityLife district of Milan last year acquired its most high-profile occupant, when Chiara Ferragni, Italy’s famous fashion blogger and influencer, moved into a Hadid-designed penthouse with a view of Isozaki’s Allianz tower as well as a glimpse of the Duomo. The luxury development has been built on the site of the old trade and design fairs that attracted presidents, popes and film stars to Milan throughout the last century. An exhibition of photographs tells the story of Milan’s industrial past.

It also features a quote from the Finnish-American architect Gottlieb Eliel Saarinen: “Always design a thing by considering its context – a chair in a room, a room in a house, a house in an environment, an environment in a city.”

In this age of superbia for Europe’s booming cities, it is tempting to add: “A city in a region, and a region in a country.”

• This article was amended on 13 November 2019 because an earlier version incorrectly stated that next year the international book fair traditionally held in Turin is transferring to Milan.