To live in the Maldives is to live in one of two worlds. Either you belong to the capital — Malé, a micro-Manhattan in the Indian Ocean — or you are out in “the islands,” among the quietest and most remote villages this side of the Arctic tundra.

It is in these places — far from the archipelago’s walled-garden resort atolls, where no Maldivians actually dwell — that the country is picking between two visions of its future, like much of the rest of Asia, but more so.

The outer islands are steadily depopulating, as the appeal of making a life through tuna fishing and coconut farming along their crushed-coral seashores shrinks. The splendid isolation may be what attracts visitors, but it seems incompatible with islanders’ aspirations in a nation modernized by global tourism.

As Maldivians give up on island life, the government feels compelled to keep building up Malé, the country’s one real city. But Malé is already pressed up hard against the limits of human habitation. By some measures, it is the most densely populated island on earth, with over a third of the country’s 520,000 people on a landmass that can be crossed by foot in about 20 minutes.

If more Maldivians are going to move there, its physical structure will need to be radically reworked. In the meantime, it is sprawling outward wherever it can: The government is surrounding Malé with sea bridges to artificial islands packed with housing projects financed by China and India.

On Jan. 22, President Mohamed Muizzu announced his otherworldly vision for an undersea tunnel between Malé proper and a land-reclamation project where Chinese investors will help build 65,000 housing units on what is now barely a sandbar.

Mr. Muizzu, a civil engineer by training, said the tunnel would “provide beautiful views of the sea” as commuters passed through it. (Feasibility to be determined.)

Humay Ghafoor, a researcher who campaigns against environmental degradation, said that “nobody does any assessments” before commissioning “massive infrastructure” projects. This allows an airport, for instance, to be built over a mangrove, destroying a whole island’s freshwater supply.

The Maldives consists of a thousand islands stretched along a 550-mile axis, each one a bit of exposed coral that grew from the rims of a prehistoric range of undersea volcanoes. These form rings called atolls — a word that comes to English from the native Dhivehi language. Most of the 188 inhabited islands have fewer than 1,000 residents.

The resorts — those airy villas floating over turquoise seas — are all on technically “uninhabited” islands. The guests are foreign, and most of the staff is, too, mainly from India and Bangladesh. In some ways, the resorts are like offshore oil rigs, pumping out nearly all of the country’s income. By design, they are divorced from Maldivian culture and abstracted from their South Asian location.

The typical inhabited island is likewise rich in sunshine and warmth and has access to a shallow lagoon, palm trees and maybe a mangrove forest. The inhabitants are highly literate, many are English-speaking and they are connected to the rest of the world by the internet, mobile data and long ferry routes.

Their traditions survive, still. Perhaps every island except Malé has a holhuashi, a covered seating platform at its harbor, sometimes circled by hanging woven chairs. Men gather to rest at midday and exchange gossip.

There is little doubt that climate change will eventually bring doom to this country, most of which is just a meter or two above sea level. But that catastrophe is thought to be a century or more away.

Instead, Maldivians are leaving the islands for the sake of their children, looking to Malé and the world beyond. When it comes to education and health care, there is no substitute for city life.

Nolhivaranfaru, a fishhook-shaped bit of powdery white sand, with a green and fertile core between its beaches, is like many of the Maldives’ inhabited islands. Flowering frangipani stand over an Islamic cemetery near its piers, centered around a centuries-old shrine to an Arab pilgrim. It takes 25 minutes by speedboat to reach the nearest landmass and two airplanes from there to get to neighboring India.

That is a journey that Maryam Asima, a 30-year-old mother of twins, made at great cost and personal hardship. She and her husband, the captain of a tourist yacht that docks 175 miles away, near Malé, had been unable to conceive. Two years ago, Ms. Asima and her sister, who was in a similar position, traveled to Kochi, India, a city of 2.1 million, where they made do on their own during 11 months of IVF treatment.

Health care remains rudimentary even on the better connected of the outer islands. Staff at the local clinic scoff at the idea of someday providing IVF. They say quietly that even most emergency care is beyond them: Any patient who needs a ventilator must be flown hundreds of miles away.

Ms. Asima, now back on the island with her 6-month-old twins, says she is satisfied with the results of her ordeal. Her sister has given her a nephew, too. With her encouragement, two other women from the island have become pregnant in the same way. The government has started offering $500 subsidies and the possibility of free air travel for families that need to go abroad for IVF.

She likes the “home feeling” of her island and hopes to send her children to school there, even if they need to travel to a nearby island to see a pediatrician. But this is not her first home: Ms. Asima was born on an even smaller island, Maavaidhoo, which was abandoned after being swamped by the Indian Ocean tsunami of 2004.

Many Maldivians have been on the move for a generation or more, leaving smaller communities for larger ones. More than anywhere else, those who can afford it go to Malé.

Thirty years ago, it was not unusual for families to send unaccompanied minors on long ferry journeys, of 20 hours or more, to live in Malé. They would stay with distant relatives or even strangers and work as pint-size housekeepers to pay for their room and board as they attended one of the country’s better schools.

Island families still send their children to study in Malé, but usually now they travel as teenagers; better primary schooling is available even in remote places.

The cramped conditions of the capital are the first challenge they face. A compact grid of streets jams pedestrians, motorbikes, workshops and luxury perfumers together like a miniature version of central Hong Kong. One-bedroom apartments rent for five times the starting salary of a government office worker.

Ajuvad, a nervous, soft-spoken 23-year-old, came to Malé at 16 to join his older siblings, six people crammed into three bedrooms. They are all professionals, with jobs as teachers and technicians. But they were raised in another world, a 36-hour ferry ride away. There, the beach was a five-minute walk away with no roads and no motorbikes, and their home was a four-bedroom house that their father, a fisherman, built himself. Their mother made fish paste and sold it to neighbors.

Ajuvad, who asked that his last name be withheld to protect his privacy, remembers the transition as being “quite a challenge.” Having to live without his parents, and without an inch of space to study alone in quiet, he said, “I thought my world had collapsed.”

Ahmed Abbas, a 39-year-old hardware salesman, had an easier time moving into Malé’s urban sprawl from a distant southern island 12 years ago. His family of six shares a two-bedroom apartment in a complex built by Chinese developers, across a sea bridge from the city proper. They spend only half of their income on rent, and he drives to the city, 25 minutes each way, twice a day.

Mr. Abbas studied and worked around South India for many years before settling down. He has seen enough of the world to appreciate his family’s perch, which they share with two love birds: Small, exotic pets are a big business in little Malé.

But he still misses the island life. Back home, it was “nice because the people are nice,” he said, “normal country people, all smiling.”