Raul Castro, who will be re-elected president when Cuba's National Assembly meets on Sunday, wants to reform the island's sclerotic economy while keeping a central role for the Communist Party.
It would be a difficult balancing act in the best of times, even for a leader with Raul's impeccable revolutionary pedigree.
Raul Castro is the younger brother of legendary Cuban leader Fidel Castro and took power only when the 86-year-old's health began to fail.
Since becoming president in 2008, he has attempted to overhaul Cuba's antiquated Soviet-style economic system, but his reforms have done little to improve the lives of ordinary Cubans.
One change has been to limit a president's time in office to two five-year terms, so Castro, who turns 82 in June, will have until February 2018 to make his mark.
His reforms come as the future of the island's economic benefactor, Venezuelan President Hugo Chavez, remains uncertain. Chavez is recovering from cancer surgery, and it's unclear whether his successor will be as generous.
Cuba has endured a US-imposed trade embargo since the 1960s and, since it failed to discover any oil in its part of the Gulf of Mexico, Havana depends heavily on cheap oil and economic aid from the leftist Venezuelan regime.
Raul Castro became leader of Cuba's military following the 1959 revolution and spent most of his career in the shadow of his more famous older brother.
He became interim president when Fidel took ill in 2006, then formally became president in 2008.
The contrast is sharp: while Fidel is warm and cheerful, Raul is taciturn and distant.
Raul speaks like a commanding officer, and rarely deviates in public from brief prepared speeches -- unlike Fidel, who could improvise and deliver flowery and colorful rhetoric for hours on end.
Raul Castro had a rare show of humor on Friday, so rare that some wondered if he was serious.
"I am going to resign. I am about to turn 82. I have the right to retire. Don't you believe me?" Castro said, smiling to reporters after accompanying Russian Prime Minister Dmitry Medvedev to the old Soviet cemetery near Havana.
Raul, unlike Fidel, also has a reputation for being a pragmatist.
His goal is to liberalize Cuba's economy and encourage more private entrepreneurship, but at the same time maintain a key role for the Cuban state through joint ventures.
He has promised to keep Cuba's free education, universal health care and free or low-cost access to cultural events.
The president is also seen as serious about battling corruption and has sent scores of officials, even former cabinet members, to prison for graft.
During his presidency, Castro has allowed Cubans to own mobile phones and computers, and to stay in swank hotels previously reserved for foreigners.
In 2010, he engaged in unprecedented talks with the Catholic Church, resulting in some 130 political prisoners being set free. This set the groundwork for Pope Benedict XVI to visit Cuba in March 2012.
In 2011, he let Cubans legally buy and sell homes and automobiles, and slashed the country's bloated bureaucracy as a cost-saving measure.
In mid-January, he even allowed Cubans to travel abroad without special exit visas or a foreign invitation, provided they have a valid passport.
Cuban dissidents are unimpressed by the reforms.
In communist Cuba, most everything -- especially the news media -- belongs to the government. There are no independent radio stations or newspapers.
Dissidents continue to demand freedom of expression and the right to form a political opposition. The regime dismisses the opponents as "mercenaries" on the US payroll.
A new National Assembly takes office on Sunday and will elect 31 members of the Council of State -- Cuba's executive branch -- and is fully expected to re-elect Castro as president.
Observers will scrutinize the Council for any sign of a possible successor.