IN PAST DECADES the United States has used force to change governments in the Caribbean basin. Nowadays the country is trying to extricate itself from wars, not get into a new one.

Yet President Donald Trump has repeatedly insisted that “all options are on the table” to remove Venezuela’s dictator, Nicolás Maduro, from power. What if he means it? Experts think a military intervention would be unwise, for many reasons. Some spoke on condition of anonymity.

A full-scale shock-and-awe invasion would require a formidable logistical and operational effort. The intervention in Panama in 1989, which removed from power Manuel Noriega, a drug-running dictator, involved nearly 26,000 troops, many of whom were already in the country. It was quickly over.

But Panama is a minnow. Venezuela is a mountainous country twice the size of Iraq. It has large cities. In such conditions, the United States’ high-tech weaponry confers less of an advantage. Each of the presumed objectives—detaining Mr Maduro, installing a new government, organising elections and allowing in aid—would be a big task, involving large numbers of boots on the ground.

A fourth complication is that any intervention has to reckon with the role of countries that back Mr Maduro’s regime, both on the ground and at the United Nations. Thousands of Cubans, including military advisers and intelligence officers but also doctors, are in the country. Luis Almagro, the secretary-general of the Organisation of American States, likens them to an “occupation army”. Russia and, more cautiously, China support Mr Maduro; both are able to veto UN backing for a military intervention, which would anyway be hugely controversial.

All this explains why, for all the talk about what may be on the table, it does not yet appear to be an imminent plan. “I can dispel the theory that there is a military option for Venezuela,” says a defence official in Washington. She denies that staff are being asked to draw up plans.

That could change if Mr Maduro hangs on for months despite a deepening humanitarian disaster and a mass exodus of refugees. American officials warn that violence against Americans (which was what triggered the intervention in Panama) would change the situation. So might any attempt to harm Mr Guaidó or his family. A military option, for all its difficulties, cannot quite be ruled out.