His supporters and family in Rome insist he has no ambitions of regaining the throne, but say he is probably the only figure with enough prestige to be able to galvanise his warring people behind a new government of national unity.
The former King has offered to play a role in establishing a transitional government should the Taleban be pushed out of power by any US attacks in the hunt for its number one enemy, Osama bin Laden.
"I'm convinced that His Majesty can play a very important role in the coming months," the United Nations envoy to Afghanistan, Francesc Vendrell, said this week after talks with the reclusive ex-monarch in Italy.
The one-time King lives in a secluded 1970s villa on the northern outskirts of Rome. The wooden front door is peeling, a small, stuffed ram's head hangs next to the stairs and a portable gas fire sits by his living-room chair.
It is a far cry from the marbled palaces, glamorous receptions and grand estates of his regal past.
Zahir Shah was born in Kabul on October 15, 1914, received part of his education in France and returned to Kabul for military training. He ascended the throne in 1933 after his father was assassinated by a deranged student.
For a number of years, the bookish King remained in the shadows, allowing three uncles to run the Government. But he gradually gained in confidence and took full control in 1953, overseeing a cautious modernisation of his backward realm.
He supported an end to purdah - the wearing of the veil - for women, used foreign cash to develop the country's medieval infrastructure and managed to keep a balance between Soviet and Western interests.
Older Afghans look back with nostalgia on his reign. "I was a teenager then and it was like a dream," says Hamid Karzai, a fellow Pashtun from Kandahar who now lives in exile in Pakistan.
The US State Department released an opinion poll this year saying that most Afghans regarded their former King as the man most likely to address the country's many problems.
"We have the feeling that a lot of Afghans, after 22 years of misery, see in their former king the last ruler that had any legitimacy and the last ruler that presided over a period of relative prosperity," Vendrell says.
In 1973, while in Italy, Zahir Shah was ousted in a bloodless coup orchestrated by his cousin and brother-in-law, Prince Daoud, ending two centuries of rule by the Durrani dynasty. He has not set foot in Afghanistan since.
"Most important for me at my age ... is to see a happy Afghanistan, an Afghanistan that at last gets rid of these 30 years of cruelty imposed upon it," Zahir Shah said in a rare interview aired by the BBC this week.
He will not find everyone ready to welcome him home with open arms.
Fundamentalist mujahideen groups accused him of paving the way for the 1978 communist takeover by sending students, doctors and Army officers for training in the Soviet Union. They also believe him to be a weak man dominated by relatives.
Moderates were disappointed he was not more vocal during his lengthy exile and say he missed an opportunity to take a major role after the Soviet withdrawal in 1989.
In Rome, the bald, hawk-eyed monarch rarely speaks in public, leaving it to his youngest son and his grandson, Mostapha Zahir, to do the talking, while his son-in-law, General Abdul Wali, always shields him from the media.
Pakistan has long been opposed to his return, favouring more Islamic groups it thinks it can influence, and some Western diplomats secretly admit they are worried that his fragile health and old age could undermine his authority.
Indeed, it says much about the bleak state of Afghan politics that despite the doubts, his is the name most often mentioned as the best choice to preside over a transition if the Taleban is chased from power by looming US attacks.
As a first step to bringing peace to his battered homeland, Zahir Shah has called for the convocation of a traditional grand council of elders, a so-called Loya Jirga, to try to rally the country's fractious Pashtun tribes and ethnic minorities behind a single government.
"I appeal to the Afghan people and to their sense of honour and patriotism to rescue us from this dangerous situation so that in the future we will have exonerated the Afghan people before God Almighty and history," he said in a radio address to Afghanistan last week.
His renewed favour with his people has more than symbolic effects. In recent days, rumours that Zahir Shah was set to return have helped push Afghanistan's struggling currency dramatically higher, especially the rate for rarely used bills printed during his reign that carry his picture.
"Rates have been improving because people think the King will do something," says money changer Haji Mohammad Rafi.
"There is a 100 per cent premium on the Shah money, but it is not used much any more because there are so few bills left," says Rafi, who has been trading money for 14 years in the Pakistani frontier town and trading hub of Peshawar.
The afghani fell to 78,500 to one US dollar shortly after the attacks on New York and Washington on September 11, but had recovered by Thursday to about 55,000 to 60,000 - near levels it was trading at before the attacks.
Bills that carry the King's picture are rare because none have been printed in decades. And with the biggest denomination note just 1000 afghanis, the bill is scarcely practical when a stack would be needed to buy just one dollar.
"You can use them if you want, but they're mostly souvenirs," says Rafi, operating on the edge of a courtyard where several money changers haggle over rates before sealing a deal with a clap of hands.
But dealers are also worried because afghanis are printed in Russia, a throwback to the decade-long Soviet invasion, and are used to finance the opposition Northern Alliance. "The Northern Alliance has a lot of currency, so the rate could deteriorate," says Haji Khalid, another dealer.
The money is smuggled from opposition areas through the north of Pakistan to Peshawar, where the bills then enter circulation in Afghanistan.
Rafi says a money transfer system to Afghanistan, which does not have a functioning banking system, is still in place, and he can send money to almost any city in the country.
"Pounds, marks, no problem," he says.
The money is handed over in Peshawar, and Rafi makes a call to Kabul where the same currency or the equivalent in afghanis or Pakistani rupees is handed over to the recipient - a system known as hawala.
He sends about $US3000 worth a day, a huge amount considering a teacher in Kabul may be paid only $US8 a month.
The money market in Peshawar is closely linked to Kabul's main Shahzada (prince) money market, which has survived 22 years of war and a disappearing economy that has forced the afghani down to its current levels from about 200 to the dollar in the early 1990s.
Another factor behind the strengthening afghani has been the soaring prices of essentials as people stockpile food and fuel in case the standoff with the US drags on. And it could strengthen further amid fears of food shortages following the withdrawal of Western aid agencies.
The former King's entourage still clings to the hope that Afghanistan can resolve its economic and political problems without another bloodbath, insisting that the Afghan people have nothing to do with bin Laden.
"The Afghan people are not terrorists. During the whole war of liberation against the Soviets, Afghan fighters did not commit a single act of violence against women or children," the former King said in a written reply to journalists' questions.
But even if a fresh war can be avoided, Afghanistan is already a shattered country and Zahir Shah will barely be able to recognise his old homeland should he ever return. His son, Wais Zahir, was 14 when he last saw Afghanistan and says the family knows what to expect.
The city he remembers survived the war against the Soviet Union only to be bombed to ruins by the civil war between mujahideen groups that followed.
He says: "When I see pictures of Kabul, I feel an immense sadness, depression and shock. If we go back, we are going to have to be very strong. We will have to rebuild our country."
- REUTERS
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