In a leaked internal document, the Pentagon has suggested ways in which it might punish allies for a perceived failure to support the US war in Iran. One such method is for America to withdraw its support for the relics of European empire, most notably regarding British control of the Falkland Islands in the South Atlantic. Keir Starmer has responded via a spokesperson that “sovereignty rests with the UK, and the islands’ right to self-determination is paramount.” Donald Trump’s threat is, of course, fantasy. Yet it is instructive about America’s foreign-policy priorities.

Argentina’s President Javier Milei hopes that his country might one day reassert control over the Falklands, but he has ruled out the use of force as a means to achieve this. He admires Margaret Thatcher. He knows about the humiliating defeat Argentina suffered at the hands of the British task force sent by Thatcher to retake the Falklands in 1982, after the military junta invaded the islands. Those islands are much better protected now than they were then. Milei is also shrewd enough to know that Trump is the world’s most unreliable ally if the going gets tough.

Still, the Pentagon discussions are not completely irrational. The Trump administration has already tilted away from Europe and towards a more assertive posture in the Americas. It’s worth remembering that during the war of 1982 there were plenty of powerful Americans — figures such as Senator Jesse Helms and Jeane Kirkpatrick, the US ambassador to the United Nations — who thought that America ought not to side with Britain against the violently anti-communist regime in Buenos Aires. It’s also worth remembering that America has a long history of opposing European colonialism, not always for entirely disinterested motives.

Trump apparently believes that Nato, a defensive alliance, should compel its members to support the United States in an offensive war that none of them wanted and which has damaged their interests. In some ways, he sees Nato much as Leonid Brezhnev saw the Warsaw Pact: not as a real alliance but as an instrument to advance the interests of one great power. Trump has threatened interventions against Greenland and Canada but he has not yet come close to attacking a Nato country; the Soviet Union, conversely, required its Warsaw Pact allies to participate in the 1968 invasion of Czechoslovakia, a fellow member.

Remembering Czechoslovakia in 1968 might, however, ring alarm bells in the Pentagon. Military superiority does not confer unlimited power. Czechoslovakia was once one of the few satellite states of the Soviet Union in which a significant number of people really believed in communism. That belief pretty much disappeared after 1968. Britain is the Czechoslovakia of Nato — the country where members of the governing class are most likely to believe in the virtues of the Atlantic alliance. A threat — even an implausible one — to a territory that still contains the graves of British servicemen who died in 1982 may change British attitudes in ways that will be hard to reverse.