El Comandante's silence has Cubans holding their breath

Fidel Castro feared it would be an assassin's bullet or perhaps an exploding cigar planted by CIA agents that would finally put him out of business as the world's longest-ruling head of government.

But despite advancing age and increasing frailty, it is something of a humiliation for El Comandante to be dethroned by an illness, albeit a serious one, which has left Cuba with its first leadership change in 47 years.

Dr Castro, 79, has revelled in his reputation as the tough guy of world politics who maintained an iron grip on his state and citizens through any adversity.

'The last time he went under the surgeon's knife, when he fell and broke his wrist a couple of years ago, even during the operation he didn't allow general anaesthesia,' said Joe Garcia, formerly of the Cuban-American National Foundation, the largest group representing exiles in the US. 'He was on his mobile phone giving orders and running the country from his hospital bed right away.'

This time, however, things are different - Dr Castro, whose overpowering presence has permeated every aspect of Cuban life since his overthrow of president Fulgencio Batista in January 1959, is unusually quiet. There are no thumping, defiant speeches from his private hospital room, or television pictures showing a smiling leader on the road to recovery. Instead, there was only a brief TV report announcing that Dr Castro's health was 'stable' and that he was in good spirits.

Given the lack of news, many among south Florida's community of 650,000 migrant Cubans believe Dr Castro may already be dead, and that the announcement is being delayed to give his vice-president and brother Raul, 75, time to cement his own position of power.

'Under these circumstances, you've got to ask what's going on,' Mr Garcia said. 'This vision of total and complete control is not there. When Ronald Reagan got shot, he was waving from his hospital bed within a week.'

In Miami, despite the uncertainty, there is a palpable feeling that change is coming. Cuban-Americans of all ages joined street parties along the main street through the city's Little Havana neighbourhood all week, celebrating Fidel Castro's demise amid blaring car horns and the din of clanking pots and pans.

Even though US intelligence sources say that these celebrations appear premature, and that Cuba and its 11 million citizens should prepare for the possibility of Fidel Castro pulling through after a long convalescence, the exile community senses the beginning of the end.

Many brought banners attacking Dr Castro and calling for the overthrow of Cuba's communist government, or simply stating Vive Cuba Libre (long live free Cuba). At the Versailles cafe and restaurant, a popular hangout for Cuban exiles, people spoke excitedly about the end of Fidel Castro's despotic rule and their hopes for the future.

'A lot of these people were forced to come here after losing their homes, properties and businesses, everything they had, to that tyrant,' Albert Rodriguez, 66, said. 'There are a lot of mixed emotions here. We have family members back in Cuba we haven't seen for decades, and everybody is talking about going back, but the older Cubans among us know that Raul is every bit as ruthless as his brother and nothing can really change until he's gone too.'

It is that ruthlessness, couched in a velvet glove, which has kept Fidel Castro in power and Cuba as a communist nation for so long despite the collapse of its former main sponsor, the Soviet Union. The dictator, analysts say, presents himself to his people as a friendly, approachable father figure looking out for the best interests of 'the family'.

'Fidel is a very personal figure,' Mr Garcia said. 'He could be your uncle, your grandfather; he's right there all the time. But that's how repression works in Cuba, it's on a familial basis. Cross Fidel, and it's your uncle that doesn't get that job in the factory, it's your cousin who doesn't get to go to college.'

Dr Castro, who turns 80 on August 13, has become more conscious of his health as he ages. In recent years he has given up his trademark cigars and has suffered several illnesses and mishaps, including the episode in October 2004 when he fell after giving a speech, fracturing a knee and arm.

A report leaked to The Miami Herald last November claimed that doctors working for the CIA concluded he was suffering from Parkinson's disease after studying videos of him falling asleep or fainting at public functions. His notoriously long rants against the US government have also become noticeably more rambling of late.

Cubans, and the world, now wait to see what the future will bring, and if the country under Raul Castro will continue in the same direction. After decades as Havana's heir apparent, the man who has headed Cuba's armed forces for the past 47 years, and who has built himself a solid reputation as 'Fidel's enforcer', is more than ready to step into his shoes.

'He can be more ruthless than Fidel and lacks his brother's charisma,' Mr Garcia said. 'He's never hesitant to play the bad guy. While Fidel played the elder statesman role [after the 1959 revolution], Raul was carrying out executions.'

According to historians, it was Raul Castro who ordered and oversaw the deaths of many military commanders, and even soldiers loyal to the old regime in the early months of La Revolucion, as Batista and his entourage fled to Spain.

Yet despite his central role in the popular uprising, Raul Castro has never been able to emulate his brother's dominance over Cuban hearts and minds. He is seen as more of a thinker, and is credited with being the driving force behind the country's agricultural reforms of the 1990s after subsidies from the former Soviet Union dried up.

With those reforms, he also knocked the first dents in the US trade embargo with Cuba, implemented in 1961 and designed to stop US dollars flowing into the country. For the first time since the revolution, American farmers were allowed to conduct business in Cuba, hinting to some observers that Raul Castro might eventually turn into more of a reformist than his hardline brother.

Jose Fabregas, 57, came to Miami in 1961 with an uncle and is one of a growing number of Cuban-Americans calling for stronger links with the US.

'Raul is ruthless, but he doesn't have the charisma of Fidel and my thought is that in order to keep control, he must open up more of a commercial relationship, expand the economy and build up the island. There definitely will be a change,' he said. 'One of things the US should do is end the blockade. It's provided an excuse for Castro for years.'

Others remain to be convinced that the transfer of power will change anything, in the short term at least. 'The long-awaited day of a Cuba without Castro may be approaching,' said Mel Martinez, the first Cuban-American to serve in the US Senate. 'Our hope and purpose should now be for a true moment of change, not a transfer from one dictator to another.'

The crisis over Fidel Castro's health has also sparked a flurry of activity in Washington, where officials say President George W. Bush is monitoring developments and stepping up his administration's planning for a transition to democracy in Cuba. The 10th occupant of the White House to wrestle with the Cuban leader since the revolution is mindful of the weighty political support that Cuban exiles give his brother Jeb Bush, governor of Florida.

In June, the US president unveiled his blueprint for hastening the transition, including more than US$80 million over two years for pro-democracy groups. Other plans include increasing the number of broadcasts from anti-Castro TV and radio stations into Cuba, and maybe increasing the US Navy and coastguard presence in the Florida Straits to prevent mass migration in either direction.

The headache of scores of Cubans heading back to their homeland, or thousands of would-be emigrants trying to make it to US shores, is something that terrifies the administration, analysts say.

'One thing this president has talked about from the beginning is his hope for the Cuban people to finally enjoy the fruits of freedom and democracy,' White House press secretary Tony Snow said. 'For the dictator to hand power to his brother ... is not a change in that status.'