(CNN)Royal visits overseas always attract a great deal of scrutiny, but none in recent memory has been quite as politically sensitive and potentially inflammatory towards the UK's closest ally than this one.
Historic royal visit to Cuba at odds with US stance
When Prince Charles and his wife, Camilla, set foot in Havana Sunday, they'll be making history by embarking on the first ever official visit to Cuba by members of the British royal family. But they're doing so at a time when much of the western world is denouncing Cuba's role in the unfolding political and humanitarian crisis in its close socialist partner, Venezuela.
It's a trip that would have seemed impossible only a handful of years ago, before former US President Barack Obama and former Cuban President Raul Castro thawed more than half a century of tense relations between the North American neighbors and their allies. But since that 2016 breakthrough, the world is a very different place.
President Donald Trump has reversed many of the Obama-era policies toward Cuba, reinstating travel and trade restrictions. His sharp rhetoric has only become more aggressive since the presidential crisis unfolded in Venezuela. The role of Cuban military and intelligence advisers serving the disputed regime of President Nicolas Maduro is one of the main concerns of the US administration and its allies.
"For decades, the socialist dictatorships of Cuba and Venezuela have propped each other up in a very corrupt bargain," Trump said in February, adding: "Maduro is not a Venezuelan patriot; he is a Cuban puppet."
US Secretary of State Mike Pompeo went further earlier this month: "No nation has done more to sustain the death and daily misery of ordinary Venezuelans, including Venezuela's military and their families, than the communists in Havana."
It's against this backdrop of American hostility that Prince Charles and the Duchess of Cornwall will spend four days in Cuba highlighting "the growing bilateral relationship with the UK and showcasing some of the cultural links between the two countries," according to a royal spokesman.
But while Charles and Camilla are the ones who'll have to navigate dinner with politicians in Havana's Palacio de la Revolucion, it's the British government who is responsible for sending them there.
"The royal family don't make these decisions," points out Andrew Lewer, a member of the UK Parliament for the governing Conservative Party. "It's the Foreign Office, so the royal family themselves shouldn't be blamed for this. Our friends in the United States, the many Cubans in Florida, will rightly be perplexed at the sight of the British royal family making a visit, going on tour, looking around the place, at a time when these despicable acts are taking place."
Another Conservative MP, Julian Lewis, says the visit will be awkward for the heir to the British throne: "It is not for a constitutional monarch on a royal visit to get sucked into political confrontation. He will constantly have to balance the need to behave diplomatically with the danger of seeming to endorse the regime and being used as a propaganda tool by it."
The fabled "soft power" of the royal family has long been used as a diplomatic tool by the British government and in this instance, the UK Foreign & Commonwealth Office confirmed the strategic value of the visit: "This is part of our longstanding approach towards Cuba of engagement and frank dialogue over the issues that divide us like human rights, but also the engagement towards progress on the matters that bridge us together," a spokesman said.
This approach to relations with Cuba could not be more different than that exhibited loudly in Washington.
Former Florida governor and now US Sen. Rick Scott has written to British Prime Minister Theresa May to protest the royal visit and is perplexed by the timing: "Why would the British government want to recognize Juan Guaido as the new President of Venezuela when we all know the Castro regime is the one propping up Maduro, dictator in Venezuela... and then at the same time have the Prince, who has unbelievable worldwide influence, go prop up the regime?"
Sen. Scott suggested that while in Cuba, Prince Charles should meet with dissidents and take a leaf from President Trump's book: "He says 'I'm going to stand for freedom and democracy' and that's exactly what Prince Charles ought to do."
No such meetings are planned during the tour, but neither are there any planned encounters with Castro, who continues to serve as first secretary of the Communist Party. The Prince and Duchess will meet current President Miguel Diaz-Canel, who recently described Trump's rhetoric towards Cuba as "warlike and dirty."
It is, of course, a sensitive time for the UK as Theresa May navigates the endgame for Brexit. Royal visits are likely to continue to play a key role in Britain's international relationships, especially in the years immediately following its departure from the European Union.
But it's the timing of this historic royal visit that makes it so contentious -- especially as the UK seeks post-Brexit trade deals. Trump is unlikely to warm to images of one of the UK's most senior representatives enjoying the hospitality of Havana.