SOMETIMES, through the fog and chatter, you get a glimpse of how the world works.

At one moment you couldn't name the person who happens to be the US Assistant Secretary of State for European and Eurasian affairs. At the next you are reminded of who really runs British foreign policy.

Philip H "Phil" Gordon, the man with the long title, gave David Cameron's Government an uncomfortable moment this week. It was less for what Mr Gordon said than for the fact that he said it publicly, with journalists around. Barack Obama's administration is not keen, it turns out, on Euroscepticism, in-out referendums, or the risk of losing its proxy voice in Europe.

This wasn't news. It has been standard Washington policy, in fact, for four decades. But that's a fact equivalent to the dog failing to bark. Why would Mr Gordon say such things now, with the calm confidence that he – just an assistant secretary, after all – would provoke a reaction from Downing Street? A simple answer: this is how American governments see the world, and Britain's place in the world.

An opinion is offered as advice, but it sounds like an instruction. For the record, Mr Gordon said: "We have a growing relationship with the EU as an institution, which has an increasing voice in the world, and we want to see a strong British voice in that EU. That is in America's interests. We welcome an outward-looking EU with Britain in it."

The veteran from the Brookings Institution, the man who headed Mr Obama's "European team" during the President's first election campaign, the favourite of the Atlantic Council, added that a British withdrawal from the EU would not, sadly, "enhance" the venerable special relationship. Instead, if push came to shove, America would work on its connections with other European nations. The EU is "a growing voice in the world and a critical partner on global issues".

Tory sceptics and Nigel Farage of UKIP were operatic in their outrage. The old Conservative mistrust of high-handed Yanks – a prejudice too often overlooked on the left – boiled to the surface. How dare the colonials (I paraphrase) intervene in the sovereign affairs of HMG and its proud Eurosceptic people? They dare because they can.

From Washington's point of view, it makes sense. Europe collectively, and despite its woes, is a larger economic power than America. Though they quibble quaintly over defence spending, the Europeans still command 15% of the planet's arms and munitions. Add that to America's grotesque overspending on defence and you have, in Nato, a force more than capable of dealing with any two other powers – let's call them Russia and China – combined.

When Mr Gordon says, therefore, that referendums "have often turned countries inwards" you don't need a GCHQ code breaker to grasp his meaning. It is irrelevant, equally, whether you are a sceptic or a europhile. A Washington administration supposedly more interested in the Pacific than the Atlantic has altered course, all of a sudden, and favoured us with its guidance.

How did we get to this? You could start, historically, with the Second World War and lend-lease. You could note the attempt to force dependence on Clement Attlee's government with a punitive loan deal. You could proceed to the long, continuing farce of an "independent" nuclear deterrent under Washington's control. You could observe the history of intelligence-sharing that turned the security service into a CIA station.

But you could equally say something simple to demonstrate what Britain has become. Would Phil Gordon have unburdened himself in such a manner in Paris or Berlin? It would never have crossed his mind. The United Kingdom is relevant to the US less for its puissance – for which the French have no word – than for the access it allows. So how many economic and trade secrets do we ship across the Atlantic, just to oblige?

When Mr Gordon was being confirmed as assistant secretary in 2009 he was given a surprisingly hard time. The surprise arose, chiefly, because one interlocutor was a Democrat, Senator Robert Menendez of New Jersey. The junior senator was disturbed because the nominee had seemed to equivocate over the facts of the Armenian genocide during the First World War, apparently for fear of upsetting Turkey, an important donor to the Brookings Institution, and strategically important to the US.

Is that abstruse enough? Geo-politics turns on abstruse connections. Sometimes they lead you to ask why quite so many British politicians have been quite so keen, for generations, to cultivate a relationship with Washington, and earn the honorific "Atlanticist". The Atlantic Council exists, in large part, to promote Nato. And Nato exists for what current purpose? Phil Gordon could tell you.

We got into Iraq because Tony Blair knew where his interests – not ours, necessarily – lay. We, if you can stand the pronoun, have been in Afghanistan for more than 11 years, with excuses beyond absurd, because a succession of Prime Ministers have declined to question their instructions. This has not been, to state the obvious, in Britain's national interest.

Mr Blair was an Atlanticist from his first days at Westminster. Gordon Brown has multiple connections beyond the foam, some decades old. Just how – or rather, why – did the Baron Robertson of Port Ellen, once plain George Robertson, get from constituency surgeries in Hamilton to the secretary-generalship of Nato? Beyond question, he was the best man for the job. Student socialism is no bar to an understanding, acquired early, of the Atlantic imperative.

You could pick them off, one by one. The simple fact is that no-one truly thrives in British politics if he – or she – neglects policy made in Washington. This week, Mr Cameron and his back benches were handed a reminder of reality. The humiliation arises from the fact that Mr Obama didn't spare time to do the job himself. But humiliation comes easily, after a while, in the higher reaches of British public life.

Nevertheless, the logic of Eurosceptic outrage deserves exploration. These are the people who sometimes claim, after all, that a north Atlantic trading partnership is the perfect equivalent to Nato, and the perfect alternative to the EU. They sometimes argue that an open economy should, indeed must, look both ways and form a bridge between continents. Now a Washington think-tanker instructs them to pay attention to the script.

If their logic holds, Phil Gordon should have been told by Downing Street to take a flying run. The Prime Minister's office did no such thing. Instead, forced into a response, it claimed that the Assistant Secretary was doing no more – who'd have guessed? – than echo David Cameron. It comes to this: our primus inter pares won't tell one of Hillary Clinton's local hands to mind his own business.

This column has suggested previously that some dealings between British politicians and the US involve old ideas of treason. As in: service to a foreign power. Since lives are not at risk in the arguments over a Euro referendum, we need not raise things to that pitch. We could still ask, reasonably, why HMG did not tell the assistant secretary for Yurp to stay out of Britain's affairs.

History will call it an irony: the colonialists colonised. But after Iraq, after Afghanistan, we need to think a little harder about definitions of sovereignty and democracy. And about old friendships.