By Matt Frei
BBC News, Havana
President Fidel Castro's younger brother Raul took centre stage at the non-aligned conference that took place in Havana at the weekend. And when the delegates were not publicly discussing matters of mutual interest, many were privately speculating over Cuba's future.
Raul Castro is acting president while his brother recovers from surgery
Until recently the jokes about Fidel Castro tended to emphasise his immortality.
Here is my favourite:
For his 80th birthday Castro is given one of those Galapagos turtles that can live for 100 years.
He declines the gift.
"The problem with pets," he explains, "is that you get so attached to them and then they die on you."
The joke was last heard before El Comandante, as he is commonly known here, was rushed to hospital with intestinal bleeding.
Now the joke is on Fidel, the charismatic and stubborn father figure who has inspired both love and fear in his subjects for almost half a century.
Today 70% of Cubans have only ever known life under him and the problem you might say is that you get attached to your leader and then he might just die on you.
Forget the obsession with Tony Blair's departure and if and when Gordon will take over.
Presidents Hugo Chavez and Fidel Castro have become close allies
Cuba has been nurtured on the curdled milk of Castroism for almost as long as Queen Elizabeth has sat on her throne.
The Commandante's towering image is hardwired into the subconscious of every Cuban.
The only moving image was new television footage of the old man in his new fatigues: a pair of spotty hospital "jim jams".
He had lost 40lb (18kg) and looked distinctly frail when talking to his hospital guest, his revolutionary understudy and new best friend, Hugo Chavez, the President of Venezuela.
It must have been galling for the Comandante to watch the summit of the Non-Aligned Movement from his hospital bed.
It should have been his finest hour.
What is the NAM?
The Non-Aligned Movement (NAM) is made up of 116 developing countries and aims to represent the political, economic and cultural interests of the developing world.
Fidel Castro has, after all, survived nine US presidents, most of whom have tried to get him killed or deposed at some stage.
He is the druid of anti-Americanism at a time when hatred of America has become trendy around the world.
Much of the guest list of the summit looked like Washington's wish list for regime change: Hugo Chavez of Venezuela, President Ahmadinejad of Iran.
Then there was Robert Mugabe of Zimbabwe and Alexander Lukashenko of Belarus.
They gathered and spoke just 90 miles off the coast of Florida - tantalizingly close.
Beyond the posturing, everyone here from the delegates to the ruling elite as well as ordinary Cubans, all keep coming back to the same question like a tongue to an infected tooth.
He looked comfortable and at ease with the leaders
What happens after Fidel?
Raul Castro, the younger brother who is himself no spring chicken at the age of 75, has been running the government in recent weeks.
Significantly, it was he who welcomed the heads of government here.
A man who has the charisma of a middle manager at a regional post office has always stood in his taller brother's shadow.
But he was launched on the international stage like a blushing debutante.
He looked comfortable and at ease with the leaders, many of whom he has, of course, met in the past.
Crucially he commands the loyalty of the Cuban army that he has run for decades and the clear impression is that the regime used this summit to show it can handle the transition.
"Tell me about Raul," I ask one of his oldest friends, a revolutionary veteran called Jorge Risquet, in a library stacked with Lenin and Marx.
"Well," he said after a long pause, "Raul is a man of few but honest words. He's a nice guy and, above all, he is very, very systematic."
Systematic! This is hardly the stuff to inspire undiluted adulation from the masses.
But do not write Raul off yet.
After all, it was the stolid FW De Klerk who ended apartheid and the dull secretary of agriculture, Mikhail Gorbachev, who disbanded the Soviet Union.
Perhaps Cuba can continue to cheat history and survive as a communist island off the shores of capitalist America.
The biggest blow Washington can deliver to its old foe is to kill with kindness, lift the embargo and deprive the regime of the excuse that all the island's ills are caused by US aggression.
But then that would be too much to expect.
From Our Own Correspondent was broadcast on Saturday, 17 September, 2006 at 1130 BST on BBC Radio 4. Please check the programme schedules for World Service transmission times.