In a recent sick-bed message to the people of Cuba, Castro told them that they had to be prepared for the worst. In conjunction with rumors that his condition is not only serious, but that he is not coping well, some analysts believe this suggests that even if he survives his current illness, he may never return to full power, although he may resume it officially.
Meanwhile, across Cuba the public has been remarkably calm, suggesting a wait-and-see attitude similar to that displayed by Spaniards during Francisco Franco's final illness. Cuba, however, is not likely to be similar to post-Franco Spain. Dictator Francisco Franco made plans for a constitutional monarchy to take over when he died, and it did. Fidel Castro wants a communist dictatorship to continue running Cuba after he is dead.
Although some reservists have been alerted for activation after Fidel took sick, security forces have actually made themselves less visible than normal. Fidel's brother Raul apparently believes he has things under control. Raul has long been commander of the armed forces, and supervised the security forces as well. That should make Raul the new dictator, if his brother dies. But the one unknown is how the many Cubans, unhappy over years of dictatorship and economic mismanagement, will push for a real change. Most of the communist dictatorships have been replaced by democracies since 1989, and all have prospered. North Korean and Cuba remain faithful to communist dogma, and people are getting tired of paying for it. Fidel had the personality and popularity to keep a lid on this, but his dour brother Raul is more accustomed to ordering people to do things, not persuading them. Perhaps aware of his shortcomings in the mass manipulation area, Raul has already said he plans to improve relations with the United States in the future. That would be the post-Fidel future, because Fidel has used bad relations with the United States as part of his act for decades. Amazingly, Fidel has been able to get away with the "threat from the north" routine ever since the 1960s, and use it to keep the impoverished and imprisoned Cuban people with him.
With Cuban dictator Fidel Castro both aging, and not well, thoughts turn to what happens after he dies. That depends on what the army does, and the army is not exactly what most people think it is. Although the Cuban Army regularly displays its aging Soviet tanks and personnel carriers, its main strength essentially lies in a large body of personnel armed and trained as light infantry. Most of the heavy ground equipment is in storage, and apparently poorly maintained, while many units rely on bicycles for transportation. On paper, with all reservists and militiamen mobilized, Cuba can probably put about a million "troops" into the field. Some active forces and specialized units aside, the state of training is not high. But that means about ten percent of the population armed, and ready to fight for whatever they believe the new (post-Castro) should be.