"Lawyers," he sighs over coffee at Bill's in Darlinghurst. "They were very rich. Very fat. They were talking only of trials and laws."

But if the young lawyer had unrealistic expectations, then it was ultimately for the betterment of humanity.

Cairo's disillusionment was, in part, what led to him becoming the much-adored founder of the International Committee of the Red Cross' orthopaedic program in Afghanistan, where he has lived for 27 years, through numerous regime changes.

Through the program, begun in 1988, Cairo has helped an estimate 100,000 disabled Afghans walk again. In 2010 he was nominated for the Nobel Peace Prize.

Cairo, 64, is in Australia briefly to deliver a talk and to meet Department of Foreign Affairs officials to discuss the worsening conditions in Afghanistan.

We are ostensibly brunching, but Cairo doesn't eat. He is sinewy, bespectacled and grey-bearded. He is the opposite of fat.

Back when he was a young (thin) lawyer, physiotherapy was just a "hobby", and it might have stayed as such, had he not suffered a tragedy aged 28.

"I had a relation at the time, and the relation ended, so I was suddenly free to decide what I wanted," he explains in his charming Italian-accented English (he means relationship).

Oh, I say knowingly, you had your heart broken.

"No, it was even worse because the person died."

I say I'm sorry. Cairo is matter of fact.

"So I said, 'What can I do now?' I cried for a while. You cannot cry always.

"There is no good side, but I was free. I had this model for people I did not want to become like."

The fat lawyers.

"So I said, 'Why not turn my hobby into a job?'"

The young Cairo joined an Italian charity which sent him to south Sudan in 1987. He spent three years there, a swift and brutal apprenticeship treating the kind of disabilities rarely seen in the West.

"When you are in Africa you have to manage yourself. There was no internet. There was no Google. If you needed a book you have to write a letter to a friend in Italy."

It was, Cairo says, "perfect" for his next posting, this time with the International Committee of the Red Cross. It was 1990 and Afghanistan was occupied by the Soviets, not that Cairo was across the geopolitical detail of the place when he was told where he was going.

"I arrive [in] Afghanistan completely unprepared but the feeling was immediately good," he recounts.

"With the Afghans there is some chemistry which I cannot explain. Maybe because I am Italian. We are very temperamental, they are temperamental."

Cairo started out running a tiny orthopaedic centre in Kabul, treating victims of war. It was the only place the disabled could come for free, to be fitted with new limbs or given wheelchairs, and get access to physical (and, later, social) rehabilitation programs.

The International Committee of the Red Cross is impartial and takes all comers, meaning a wounded policeman might have to queue next to a maimed Taliban soldier.

"Intentionally we made [the Taliban] wait sitting in a place where they could see all the disabled coming in," Cairo says. "They saw they were all the same. Disability flattens everything."

It was soon apparent that war victims accounted for only a minority of disabled people in Afghanistan.

As word got around about the wonders the centre was dispensing, scores of others began literally queuing outside the centre – those with congenital deformities, car accident victims, polio patients and cerebral palsy sufferers.

"It was embarrassing, it was a nonsense," says Cairo of the restrictive policy. "They are all war victims. Forty years of war creates a disaster in the health system and the economy."

So in 1995 the centre threw its doors completely open, and Cairo and his team were faced with many cases far more complex than young men who have had their limbs blown off.

"Treating war victims is easy," he says. They are young, fit men who are motivated in rehab.

But those who have been disabled since childhood require more complex care. They may have been sheltered by their families and not educated, or they may be depressed after years of inactivity.

For a while the centre employed psychologists to assist with social rehabilitation, but that didn't work, Cairo says.

Instead, in 1996 the centre began to adopt a policy of positive discrimination. Disabled people were trained as physiotherapists, brought in as administrative staff and hired to work in the (very physical) job of prosthetic limb production in the centre's factory.

Cairo soon realised the psychological benefit of this was inestimable.

Cairo tells the tale of a depressed 22-year-old former soldier who came in recently. He had lost two legs and one arm and only wanted a wheelchair.

"But we knew with prosthetics he could walk," says Cairo.

"I sent him to talk to a physiotherapist who was a double amputee. They talk and talk and talk. I saw that eventually the physio was pulling up his trousers and showing the new patient his legs.

"And I understood that it was done."

Cairo may be thin and unassuming, but his ambitions are not.

The ICRC orthopaedic program now runs seven centres across Afghanistan. It also sends teachers into the homes of disabled children unable to attend school, and runs micro-credit and vocational training programs.

Being Italian, Cairo believes it is not enough to live a life that is purely useful, or functional. He wants his patients to experience pleasure too.

"Why, because I am a double or triple amputee, should I not be entitled to joy, to fun?" he asks.

Again, being Italian, Cairo decided a good object of passion for his patients was sport. So the ICRC now organises basketball, football and volleyball competitions for the disabled.

The men's basketball team even travelled to Japan last year to play in the qualifiers for the 2016 Rio Paralympics. (They didn't make it, but they did paddle in the ocean for the first time.)

"You should see the transformation of these people. They were ashamed of their body because their body is not so beautiful," Cairo says. "Now they are muscled and they use a T-shirt three size smaller to show the muscles. Now there are people to clap them and call their name."

But Cairo does not want to give the impression he has resolved the problems of a country with famously irresolvable problems.

"I have to tell you something very sad," he says. "I don't want to tell you we are solving all the problems because we are not. The ratio between physically and socially integrated in our activities is 1 to 30."

The security situation is also deteriorating in Afghanistan, with civilian casualties soaring this year.

Afghans, Cairo says, worry the rest of the world has forgotten them.

"I don't know if I was an Afghan what I would do. I think the only thing to do is to leave the country."

And yet, he has no plans to leave it himself. He holidays in Milan, where he has an apartment, and at his house on Lake Maggiore, near the Swiss Alps. He reads widely, most recently the new Harry Potter book, and the Elena Ferrante novels (His review: "I want to slap those two friends, always conflicting each other!")

For eight years, Cairo has been working on his own novel, a saga set in Afghanistan. He has a first draft of 350 pages.

A saga, he says, "cannot be short".