Flying out of New York from LaGuardia, the first leg of the journey was a local commuter plane to DC — so it cut low over the bottom of the city (looking for the river someone joked uneasily) and then wheeled south in the night. In that moment you get the whole of Manhattan laid out before you, every detail etched in lights, the grids and drives around the edges, Broadway cutting diagonally across, the dark middle of Central Park, the surrounding waters.

New York is not America — indeed, in some ways it’s the last bit of Europe before you hit America — but it’s got enough of the energy and verve of the whole thing to stand as some sort of condensation of Americanness. Especially when, half a day later, bleary-eyed, you hit London, and wonder if the Airbus passed through some sort of Life on Mars style effect in mid-Atlantic. How the hell did we wind up back in 1973? Why does everyone look so frikkin poor and tired? Is the whole country shopping at the same discount store? What was that grey stuff hanging off all of of them? Oh. Skin. I get it.

A year and a bit after touching down in Charleston of all places, it had been high time to do something most Americans never do, and that is go somewhere else for the purposes of comparison. Mexico, yes, but even with a good grasp of the language, Mexico would take months to understand on its own terms, much less serve as some useful contrast — unless you were comparing the global South and the global North. No, to really remind oneself of what America actually is, it has to be somewhere close in income and tongue but nevertheless utterly different. Besides, I needed to avail myself of the NHS, and it was cheaper to fly across the Atlantic than it was to get a full check-up from a US doctor.

So what are the preliminary findings? On America I mean, not from the NHS. Well, the first thing that strikes you, the first thing about America that you remember backwards as new and surprising, is the standardisation of it, the degree of shiny uniformity in the US, in the chain stores and restaurants, the identical product lines, the architecture of mall and sprawl. The US has its areas of dilapidation and decay — it’s called Michigan — as I’ve made clear in previous reports, but its cultural trajectory, its deep urge, has been towards a sort of consumerist Maoism, a sort of radical uniformity and historyless newness, in suburbs, in freeways, in mall design, in the furniture of everyday experience.

The UK has more than its fair share of that, but its chain stores are set within more varied — and rundown and wheezing and grimy — given situations, accumulated landscapes. History, in a way, is just grime laid sufficiently deep to become visible in its own right, and America’s passion has been to annihilate it in an urge towards total newness, shininess, consumption.

Like a specialist in some minute field of design, prolonged exposure to this new world tends to train you in observation of differences of detail otherwise invisible to the naked eye. The first time you hit a town that is nothing but the strip of chain restaurants that greet you as you slow down and wave you goodbye as you speed up again, it is impossible to see anything but a tangle of plastic.

After a while it becomes a landscape brimming with significance — the subtle yet telling differences in mood, menu and being of a TGI Friday’s from an Applebees from a Popeye’s Chicken and Biscuit Shack. The way that the coffee-stand at the servo has milk sachets in eight different flavours, just in case you desperately want an irish mint crème latte at two in the morning on route 71 — and all laid out in exactly the same style in every outlet, so that the experience won’t be compromised, so that it is in some way, perfectible. Mao meets Mother Shaker — “there is no dust in heaven!” — meets Andy Warhol’s fey naïf observation that “everything’s becoming the same and that’s good. Like I’m drinkinga coke and a bum’s drinking a coke, and it’s the same, so why can’t it happen that way and not like in communism?”

In England? In England there’s coffee, and damn lucky you are to get it, because even a decade ago you really couldn’t. There is the particularity of nothing working, there is the variation of the small and piece-meal, so that every corner store you go into is different, unique, a little Moghul empire. London does not look like an endlessly repeated pattern of the same material, experience has a shape, the world resists your immediate consumption of it by taking on new patterns.

And of course there is the rudeness. Or at least the absence of courtesy. For with the perfection of surface in American objects, there is a matching process for American objects, a courtesy that is both real and false (that’s the nature of courtesy), and which has escalated year on year to the point where it threatens to become a deadened courtly ritual. Someone holds a door open for you and what is required is not merely “thank you”, still less “thanks” but a “why thank you very much” to which a reply of sorts should go, “why you’re most very welcome”, this demanding a third return of “uh huh”, which acknowledges the end of the exchange.

Repeat effectively for shops, phone inquiries, random encounters etc etc, until you go mad. Nothing reminds you more of the profound cultural difference than this divergence of basic comportment between Europe and America. Try saying “why you’re most very welcome” to a Brit who grunts “Ta” as you hold a heavy door open, and you’re likely to be thumped, having been assessed as taking the piss.

There’s more, much more — going back into a place where the newspapers all have nine opinion columns by people with names like “Sebastian Shakespeare” and remembering that the joint is rigged, always was, but having departed a place where newspapers have more or less ceased to exist in any form worthy the name. From a place where the TV is so choked with pharmaceutical ads (“side effects may include a rare liver toxicity and sudden death has been reported, so don’t switch if your existing treatment is effective”) to one where the process for a bit of blood work and a chest x-ray has all the customer care of a POW delousing on Eastern front 1945 and above everything the ever-spreading presence of God in everyday American life, from surviving an avalanche to getting a promotion at the Applebee’s. What’s interesting is the way in which the current economic circumstances are throwing us all towards the same place.

Leaving New York things were looking bad. By the time we were wheels down at Heathrow, the IMF had announced that the global economy had effectively stopped functioning, with trade down 45% in the gathering recession/depression. The UK would be particularly badly hit it said — and I defy even the most ardent anti-socialist not to feel sorry for Gordon Brown at a purely human level — with a 2.7% contraction. The US Fed teetered on the edge of dropping the baselines interest rate to 0 (from 0.25%) and presumably decided that any liquidity effect would be swamped by the negative psychological effect of making money free of charge. Everyone is talking in terms of the years that such a recession/depression might consume.

Thus for all their differences, the dominant mood in both societies is one of bewilderment. In the US, the cultural legitimation of capitalism has been so given over to consumption as a quasi-spiritual act that the prospect of its disappearance, of the elevator to nowhere suddenly reaching the top, cannot really be assimilated to current experience. In the UK, the social contract that Labour would run a social market, emphasis on the latter, society and that growing wage inequality would be compensated for by vast improvements in education, health, urban amenity, has barely been borne out — and now appears to be dead-stopped in its tracks.

To reverse Tolstoy, all happy societies are different, but unhappy societies find the same discontent — a sudden revelation that the version they’ve been sold doesn’t add together. It will be interesting to see how, here, across the Atlantic, and in the more excitable continent, people react to this current collapse, which is not merely a financial crisis, but the outer sign of a cultural crisis of capitalism, a problem well beyond a bailout, or a chirpy courtesy greeting, or a pint.