The US war machine has turned its sights on Cuba. Marco Rubio, the Cuban-American secretary of state who has long craved the fall of the island’s communist government, made that clear again last week. While professing a preference for a “negotiated settlement”, he said the chances of a deal were “not high”. A couple of months ago, I saw up close the economic devastation already inflicted by decades of US siege – and, since January, by a crippling oil blockade introduced by Donald Trump.

The US has now charged the country’s former president Raúl Castro with conspiracy to kill US nationals, four counts of murder and two counts of destruction of aircraft over the downing of two planes in 1996. The evidence points increasingly in one direction: it is all grimly reminiscent of the indictment of Venezuela’s Nicolás Maduro, used to justify his kidnapping by US forces.

Meanwhile, the Trump administration is leaking intelligence claiming that Cuba has acquired more than 300 military drones, supposedly to attack the US base at Guantánamo Bay. “It’s a growing threat,” claimed one anonymous “senior US official”. The idea that, after several decades of tense relations with the US, a drastically weakened Cuba would suddenly launch an attack on the superpower only 90 miles from its shores, inviting overwhelming retribution, is plainly a fantasy. It is a desperate, threadbare homage to the “weapons of mass destruction” pretext used to invade Iraq.

Trump is hardly keeping his intentions secret. “I do believe I’ll be … having the honour of taking Cuba,” he declared in March, reminiscent of the 19th-century European colonialists who carved up Africa. “[I] think I could do anything I want with it,” he added for good measure. Days ago, the USS Nimitz – the US Navy’s oldest aircraft carrier – arrived in the Caribbean, supposedly for a maritime exercise.

With the US “humiliated” by Iran, as Germany’s chancellor, Friedrich Merz, put it, you might think Trump’s appetite for conflict would be diminished. But failure does not necessarily restrain declining powers. It can make them more dangerous. Trump and his team have surely convinced themselves that conquering the Caribbean island that has defied Washington for nearly seven decades might scrub away the defeats and restore the aura of US military supremacy.

What would that mean in practice? US economic warfare has sought to grind Cubans down, and to a significant degree it has clearly succeeded. Ordinary citizens I spoke to were exhausted. One taxi driver – proud of his pristinely polished red 1957 Ford convertible – told me the price he paid for petrol had jumped from $1.20 a litre to $8. The average monthly salary in Cuba is about $16. Medical staff find it increasingly unaffordable to travel to hospitals, which lack crucial medicines.

Some citizens were clear about who was to blame. “Donald Trump,” one man bluntly put it to me in Havana’s main shopping street. Others simply wanted the nightmare to end – whatever that meant. “Cubans live on hope,” a taxi driver told me. “But something has to happen, because the people can’t take it any longer.” He didn’t know whether to blame the government or the embargo, but concluded his rulers’ policies must be at fault.

“It is undeniable that the government’s popularity is at an all-time low,” the Cuban journalist Daniel Montero told me, “and the worse the conditions are, the less people support the government. In that sense, the sanctions are succeeding.” That is surely the US calculation: that Cubans will be so exhausted by an intolerable, externally imposed economic nightmare that they will acquiesce to anything that promises to end it.

Cuba certainly does not possess military capabilities remotely comparable with Iran’s, or indeed its geographical advantages. If Washington really wants to invade and occupy an economically ravaged island of about 11 million people, then it can. That doesn’t mean there will not be a fight. It is notable that when the US attacked Caracas in January, 32 Cuban troops died resisting. If Cuban soldiers were willing to make that sacrifice for Venezuela, what would they do for the sovereignty of their own nation?

Some citizens express defiance, too. “Cubans have always defended ourselves – with a machete, with a stick,” one painter told me. It’s a Cuban tradition going back to the 16th century, he said, to the Indigenous leader Hatuey who fought the Spanish invaders. “I don’t think any Americans will come here and try to impose their will because history has shown them that they can’t.”

Perhaps Trump will secure his “mission accomplished” moment. But what would that mean for Cuba? Before the 1959 revolution, the island was the virtual colony of its neighbour, its railroads, sugar production, mines and utilities dominated by US companies. There should be little doubt about what Trump has planned. Who can forget the grotesque AI video of Gaza that he posted, portraying the apocalyptic rubble transformed into a Trump-branded luxury development of yachts and skyscrapers?

Perhaps Trump sees Cuba as a cash cow for him and his cronies. Its economy could be prised open for US multinationals – not least Cuba’s renowned, but now tottering, healthcare system. There is no obvious opposition figure, and the US would surely install a stooge. And those Cubans enraged by the theft of their country might face the same hideous violence inflicted on Iraqi and Afghan civilians by US firepower.

Trump has one advantage over previous US presidents: he doesn’t pretend to be interested in liberating other peoples. A US war on Cuba would be driven by a desire to reverse US humiliation and by greed. The profits would flow to US elites, but the wreckage would be left to ordinary Cubans.

• Owen Jones is a Guardian columnist