Having presumably gazed deeply into his crystal ball before a meeting with journalists in 1973, Fidel Castro acidly remarked that the United States would talk to Cuba when there was a black president in the White House and a Latin American pope in the Vatican. And what prescience! The visit of Barack Obama this week makes him the first US president to set foot on the sun-kissed shores of the Caribbean island since Coolidge in 1928. Moreover, the personal, even cordial, meeting between the US premier and his Cuban counterpart, Raúl Castro, marks progress in the normalizing of relations between the two nations and, according to the President himself, the laying to rest of the last vestiges of the Cold War

But leaving aside the lofty rhetoric and personal rapport of the leaders for one moment, actual concrete outcomes of Mr Obama’s flying visit are hard to come by.

Cuba looks barely closer to opening up to the outside world than it did before; despite the exhortations of the US President, there will be understandable reticence on the part of the government in Havana to open the floodgates of economic liberalism just yet, with suspicions abounding as to the impact of the free market not just on Cuba’s economy, but also on the top-down authority held by the Communist Party.

On the other side of the Straits of Florida, stringent travel restrictions to Cuba remain in place for US citizens, while the economic embargo imposed on the nation by the USA since 1962 still holds firm in the face of UN protest. And for all his posturing, Mr Obama will face an uphill struggle trying to push legislation lifting the embargo through Congress; the Lower House rests in the hands of a Republican Party that has considered Havana akin to Milton’s Pandæmonium for over half a century.

These, along with an assortment of other grievances on both sides – from returning the strategic US military base at Guantánamo Bay to Cuban sovereignty, to confronting the Castro regime with a track record on the treatment of dissidents that has won it few friends at Human Rights Watch – do cast something of shadow on the few slim chinks of light emerging from the Obama visit; the news that an American chain has put pen to paper on a deal to manage three Havana hotels or that  Airbnb runs a burgeoning business in the communist state. Bizarrely, Che Guevara’s favourite seaside resort is now apparently a kite-surfing mecca. A cynic may dismiss these modest developments as window-dressing, but an optimist might helpfully suggest that perhaps tourism can succeed where 50 years of political slanging matches have patently failed.

Not forgetting, of course, the power of personality politics – and that is not a reference to Mr Obama’s obvious charisma.

Dip into the pages of Granma, the official newspaper of the Cuban Communist Party, and the reader will be treated to the indispensable Reflections of Fidel and the Discourses of Raúl. It is difficult to overestimate the hold the Castro brothers – particularly the older and more-accomplished Fidel – have over Cuba and the hearts of its people. Not only have six decades of rule woven them into the fabric of Cuban political life, but they still retain the political capital of liberating the island from the brutal rule of Fulgencio Batista in 1959.

The elder Castro, despite officially retiring in 2006 and appearing increasingly mummified in public appearances, is believed to maintain huge influence over policymaking in Havana and makes no secret of his mistrust of all things American: Indeed, he turned down the opportunity to meet Mr Obama during his visit, instead opting for a pow wow with leftist Venezuelan premier (and cycling enthusiast) Nicolás Maduro.

The Castro brothers are the perennial survivors in the region, an accomplishment they achieved in spite of the best efforts of the CIA, and it is impossibly unlikely that three days of even the best Obama charm and rhetoric will undo the legacy of a lifetime of confrontation. But time marches on, and neither Fidel nor Raúl is getting any younger. With no obvious order of succession in place, a Castro-sized hole will be left at the heart of Cuban politics. The political change Obama is certainly unable to achieve in a few days, the Reaper may be able to in a few years.

In the immediate term, Cuba could be in for a touristic Perestroika without the prospect of a political Glasnost anytime soon. Looking further ahead, the hope in the US State Department must be that enough cooing overtures and nudges in the right direction will lay the foundations for a more open and liberal post-Castro Cuba.

As an added bonus, improving relations with its Caribbean arch-rival could do much to stem the flow of anti-American rhetoric that has emerged from left-of-centre governments across Latin America, above all in Venezuela and Ecuador. Havana had been instrumental in cementing a broadly anti-US bloc in the region, most notably propping up the Venezuelan healthcare system with Cuban doctors in return for cut-price oil. With his whistle-stop to the region, Mr Obama – now in Argentina – is clearly making an effort to present a new face to local leaders and begin the long process of smoothing over the somewhat chequered history of US involvement in the region.

Perhaps now the international community can feel it is getting its Nobel Peace Laureate’s worth.