It is hard to understand what the US thinks it is achieving by encouraging Britain to negotiate away the rights of the Falkland Islanders. Yet that is exactly what Washington is doing. Starting with the notorious 2010 press conference with then-Secretary of State Hillary Clinton and Argentine President Cristina Kirchner, a string of US officials have urged Britain to negotiate with Argentina.

When David Cameron visited the US last spring, he came away with what he thought was a promise from President Obama to “stop prodding Britain and Argentina to talk to each other”. That promise was broken almost immediately by the State Department, which called for the issue to be “resolved between Argentina and England”.

It’s depressing that the State Department doesn’t know the difference between England and the United Kingdom. But US policy is worse. The risk that Argentina will invade the islands is low, but it’s not zero. We know from Wikileaks that Clinton herself was worried about the possibility in 2010. And if Argentina should launch an invasion – or a stunt occupation of one of the smaller islands – the US would be partly responsible for encouraging its aggression.

Even the current Argentina campaign against cruise ships calling on the Falklands and fishing vessels that work its waters, should be objectionable to the US. Every year, the US Navy conducts what it calls “Freedom of Navigation” or FON exercises. These operations are potent symbols of the US commitment to the freedom of the seas.

In a FON exercise, US military units transit a disputed area of the ocean – such as the Gulf of Sidra, claimed by Libya – to make it clear that the US does not accept the unlawful claim. Argentina’s campaign is an effort to intimidate lawful commerce, a campaign that has even targeted passengers seeking to leave cruise ships during port calls in Buenos Aires. The US should condemn this campaign outright.

Right now, the Falkland Islands have little economic significance and no strategic value. But the discovery of oil and gas deposits in the surrounding waters could well change that. According to the British Geological Survey, the North Falkland basin may be the second richest such deposit in the world, with reserves of crude oil four times as large as those of the entire United States. The US is hardly the only country with a stake in those reserves. They matter to the islands, and they matter to the French energy giant EDF, which is already working in the area. But Texas-based Noble Energy has signed an exploration deal worth over $200m with the islands.

Argentina has a track record of nationalising foreign-owned oil companies, whereas the islands bid fair to become a significant producer owned by a friendly people who welcome US investment. It’s hard to understand why the US would want to upset that prospect.

The Argentine claims to the islands have been debunked many times. If the islands belong to Argentina because they are more than 300 miles off the Argentine coast, then certainly Jersey belongs to France and the Canary Islands belong to Morocco. If the islands belong to Argentina because Spain once claimed them, then surely Alaska belongs to Russia, which sold it to the US in 1867 without consulting any of its inhabitants, a good many of whom were Russians.

Argentina likes to cite UN resolutions on colonialism dating from the 1960s to support its claim. But those are General Assembly resolutions, which the UN Charter states are merely recommendations. The idea that the islands are an exercise in British colonialism is laughable. If anyone in the area is a colonist, it is the Kirchner family, which arrived in Argentina much more recently than the inhabitants of the islands settled in the South Atlantic.

Certainly, the islands are an anomaly: a British Overseas Territory thousands of miles from Britain. But the world is full of anomalies, and in many cases, the world is the richer for them. Hawaii is a US state in the middle of the Pacific Ocean. The Isle of Man is a Crown Dependency in the middle of the Irish Sea. The islands of Saint Pierre and Miquelon, off Newfoundland, are governed by France. The Dodecanese Islands are off the coast of Turkey, but belong to Greece. The Channel Islands are British, not French.

Ironing out all these anomalies would be an endless job, and would do nothing but create new hostilities. The wisest thing to do is to leave them be, especially when they reflect the will of the people who live there. And that is really what is at stake in the South Atlantic. There is every reason to believe that the weekend’s Falklands referendum will confirm that the islanders are and want to remain British. That should be the end of this fake controversy.

What is particularly irritating is that the US knows Argentina’s game. As Clinton put it in her Wikileaks cable, she feared that Kirchner might adopt “a bellicose stand as a way to distract the Argentine populace from economic problems at home”. It would be hard to write a more concise and accurate summary of the Argentine policy than that. Full marks to Clinton.

And yet Clinton played the Argentine game by calling for negotiations. It’s one thing to be fooled; it’s quite another to recognise the truth and then decide to play the fool anyhow. The only reasonable conclusion is that the Obama administration believes that the Falklands are a freebie, that since Argentina won’t invade, appeasing it is a costless gesture.

But it’s not costless. By siding with Argentina, the US is wronging Britain and the islanders. And it’s signalling to every other troublemaker out there with a spurious territorial claim that if you make enough noise, the US might just sidle up to you and start singing your tune. There are no freebies in international affairs. It’s time for the US to stop pretending that there are.