Donald Trump observed blithely last week that if his cherished tariff regime is struck down by the US supreme court, he may need to “unwind” some of the trade deals struck since he declared “liberation day” in April.

It was a reminder, as if it were needed, that nothing about Trump’s economic policy is set in stone. Not only does the ageing president alter his demands on a whim, but it is unclear to what extent he has the power to make them stick.

Yet even if the “reciprocal” tariffs first announced on 2 April are rolled back, they are only one aspect of a much wider assault on the last vestiges of what was once known as the “Washington consensus”.

To name just a few of Trump’s recent interventions, he has taken a 10% government stake in the US tech company Intel, demanded 15% of the revenue of Nvidia’s chip sales to China and suggested the chief executive of Goldman Sachs should go.

This at the same as taking a sledgehammer to Federal Reserve independence by lobbing insults at the chair, Jerome Powell, and trying to sack Lisa Cook from the central bank’s board.

The head of the Bureau of Labor Statistics was removed by Trump after a run of poor jobs data; the chief of the National Labor Relations Board, Jennifer Abruzzo, was fired, too.

The tech bros who back Trump loathe the NLRB for its role in upholding workers’ rights – mandating unionisation ballots at Amazon warehouses, for example.

Trump’s approach is simultaneously systematic, in its determination to smash existing norms, and utterly chaotic. It is hard to categorise: corporate America is being unleashed – through the wilful destruction of environmental and labour standards, for example – and brought to heel.

The leftwing Democratic party senator Bernie Sanders welcomed Trump’s efforts to take a stake in Intel in exchange for government grants, for example – something he advocated in the Guardian back in 2022 – while some Republicans have condemned the approach as (heaven forbid) “socialism”.

Partly because it coincides with the AI-fuelled stock boom that has propelled the value of tech companies into the stratosphere, the market response to this torching of the status quo has so far been modest.

Whatever emerges from another three and a half years of this maelstrom is likely to be unrecognisable as the US economic model of recent decades.

Its destruction has not happened overnight. The days were already long gone when the US, as the world’s undisputed economic superpower, could export free market, financialised capitalism worldwide.

After the 2008 crash, the conditions for which were created in Wall Street boardrooms, any moral or practical claim the US had to offer an economic example to other nations evaporated.

As the turmoil rippled out through the global economy, and the US government responded by bailing out large chunks of its financial sector, the lie of laissez-faire was laid bare.

The crisis exposed the risks of turbocharged capitalism to countries outside the US, too – not least in the former Soviet bloc – that had been advised to adopt the model wholesale.

As Ivan Krastev and Stephen Holmes put it in their compelling polemic The Light that Failed, “confidence that the political economy of the west was a model for the future of mankind had been linked to the belief that western elites knew what they were doing. Suddenly it was obvious that they didn’t.”

Back home in the US, meanwhile – as in the UK – the perception that banks had been bailed out, while the galaxy brains behind the crisis got off scot-free, sowed the seeds of a corrosive sense of injustice.

Similarly, even before the crash, the idea that ever-expanding free trade brings economic benefits was bumping up against the fact that even if that is true in aggregate, for workers across the US rust belt, just as in the UK’s former manufacturing heartlands, it brought deindustrialisation and unemployment.

This was fertile ground for Trump’s populist economic message. His first-term China tariffs were, with hindsight, a relatively modest stab at, as he saw it, tilting the playing field back towards the US.

Joe Biden did not unwind those tariffs, which went with the grain of geopolitics, as any hopes that economic liberalisation would bring China into the fold of democracies were sadly dashed, and President Xi’s regime took on an increasingly authoritarian bent.

Biden also took a muscular approach to the state’s role in the economy, with the billions in grants and loans distributed under the Inflation Reduction Act linked to national priorities of cutting carbon emissions and creating jobs.

So the idea that before Trump arrived on the scene, free market US capitalism was motoring along unchallenged is misleading, but the pace at which he is crushing its remaining norms is extraordinary.

There is ample ground for legitimate disagreement here: taxpayer stakes in strategic companies are much more common in European economies, for example. Trump may be laying down tracks that future US governments with different priorities could follow.

Given that it is so unclear even what kind of economy he is groping towards, the overriding sense for the moment is of radical uncertainty. Friday’s weak US payrolls data, with the unemployment rate close to a four-year high, suggested companies may be responding with caution.

Investors appear to have decided to avert their eyes for now, buoyed up by the prospect of Fed rate cuts, and the mega returns of the tech companies. However, with every chaotic week that passes, the risks must increase – and as the UK has learned in the wake of the Liz Truss debacle, economic credibility is quicker to lose than to rebuild.

Donald Trump is a risk-taker sounding a necessary wake-up call to a stale status quo, Peter Mandelson has told the Ditchley Foundation in a speech before Trump’s second state visit to the UK this month.

The UK’s ambassador to Washington portrayed Trump as a harbinger of a new force in politics at a time when business as usual no longer works for fed-up voters.

The bulk of the speech was focused on a call for a US-UK technology partnership covering AI, quantum computing and rare-earth minerals as part of efforts to win a competition with China that Lord Mandelson said would shape this century.

He said that such a partnership with the US had the potential to be as important as the security relationship the US and UK forged in the second world war, adding: “If China wins the race for technological dominance in the coming decades, every facet of our lives is going to be affected.”

The first steps to that partnership are likely to be unveiled during Trump’s state visit, including new commitments for cheap nuclear energy to power the AI revolution.

Mandelson, although a fierce pro-European, also said Brexit had not made the UK less relevant to the US, but by freeing the UK from European regulatory burdens had made Britain a more attractive site for US investors.

Critics of Mandelson’s interpretation of Trump’s populism will argue that it assumes a set of common values between Trump’s Maga movement and European liberal democracy that is fading.

In his pitch for a close US-UK alliance, he made no mention of key points of difference including Gaza, the international rule of law, Trump’s inability to see that Vladimir Putin is stalling in Ukraine, or Trump’s creeping domestic authoritarianism.

Insisting he was not cast in the role of Trump’s “explainer-in-chief” and denying there was any need to be sycophantic with the Trump team, he praised the US president for identifying the anxieties gripping millions of impatient voters deprived of meaningful work.

He accused those arguing for a pivot away from Trump’s America of “lazy thinking”, arguing that the America First credo on the climate crisis, US aid cuts and trade did not preclude a close partnership.

He said: “The president may not follow the traditional rulebook or conventional practice, but he is a risk-taker in a world where a ‘business as usual’ approach no longer works.

“Indeed, he seems to have an ironclad stomach for political risk, both at home and abroad – convening other nations and intervening in conflicts that other presidents would have thought endlessly about before descending into an analysis paralysis and gradual incrementalism.

“Yet – and this is not well understood – although the Trumpian national security strategy is called ‘America First’, it does not actually mean ‘America Alone’.

“We see him leverage America’s heft to put the right people in the room and hammer out compromises in order to grind out concessions.

“I am not just thinking of Ukraine where the president has brought fresh energy to efforts to end Putin’s brutal invasion and bring peace to that region. If the president were so indifferent to the rest of the world, if he was so in love with America alone, he would not have intervened in multiple spheres of conflict over the last seven months.

“Furthermore, the ‘international order’ people claim he has disrupted and the calm he has allegedly shattered was already at breaking point. So, I would argue that Trump is more consequence than cause of the upheaval we are experiencing.”

He continued: “He will not always get everything right but with his Sharpie pen and freewheeling Oval Office media sprays he has sounded a deafening wake-up call to the international old guard.

“And the president is right about the status quo failing from America’s point of view. The world has rested on the willingness of the US to act as sheriff, to form a posse whenever anything went wrong, a world in which America’s allies could fall in behind – not always that close behind either – and then allow the US to do most of the heavy lifting.”

Going further than the UK’s official line, he praised Trump’s military attack on Iran, saying: “Trump understands the positive coercive power of traditional American deterrence, deterring adversaries through a blend of strength and strategic unpredictability, as we saw in his decisive action on Iran’s nuclear programme. Well beyond their military impact, these strikes gave a swathe of malign foreign regimes pause for thought.”

The vaulted arches of New York’s Grand Central station are recognisable even to those who have never taken a train into the Big Apple. But they could very easily have been a sight visible in central London.

Shelved 172-year-old architectural drawings by Perceval Parsons show how he envisioned a new London railway connecting the growing number of lines coming into the city to a huge main terminal by the Thames.

The drawings of London’s own Grand Central Station, which are being put on open sale for the first time to mark the 200th anniversary of the first public passenger railway, show a scheme that would have given the capital of the UK a very different look today.

The station was to be located at Great Scotland Yard, close to the modern-day Embankment tube station, and would have boasted an ornamental frontage about 800ft (245 metres) in length.

Multiple entrances would lead to a “spacious hall about 300ft long and facing them would be a range of pay offices with the names of each railway above”, Parsons wrote in his plans in 1853. There would have been eight arrival platforms and eight for departure.

He described the cost of the project as a “comparatively small expense”.

The seven-hectare (18-acre) site of the proposed station contained “only a few sheds and outhouses of inconsiderable value” and was “covered with mud sending forth anything but agreeable or wholesome odours”.

“The great desideratum of a connecting link to unite the termini of the various metropolitan railways, and at the same time afford them access to the heart of London, has long been admitted,” Parsons wrote, “and a line that would effect this, and at the same time give a like accommodation to the principal suburbs, would be of still greater importance”.

The proposal was supported by Robert Stephenson, chief engineer of the London and Birmingham Railway and son of George Stephenson, the so-called “father of railways”, but the Crimean war sapped appetite for expensive projects and it was quietly forgotten.

The prospectus, including two large folded maps, has a price of £1,450, and is one of 200 items featuring in a new railway catalogue compiled by Joshua Clayton at Jarndyce antiquarian booksellers that will be on sale at the York book fair this week.

Other items on sale in the catalogue include a letter from George Stephenson to his son in 1834 and another from Isambard Kingdom Brunel dated 1838, as well as travellers’ guides, timetables, original manuscripts and documents dating from the early years of steam locomotives.

The 1840s saw an explosion in the construction of railways, known as the British railway “mania”, but various tentative plans to connect central London were ditched after the banking crisis of 1847.

In 1846, a royal commission also recommended that the construction of terminals in central London should be avoided, a warning that ultimately led to the start of the construction of the underground system in 1860.

Parsons proposed a London railway that would follow a route from Brentford in west London to Hammersmith and through Kensington and Chelsea.

From there, he wrote, it would run across Victoria Street and “through a low part of Westminster” before “passing close against the inside of the first pier of Hungerford Bridge and under the first arch of Waterloo Bridge, enclosing all that immense flat comprised in the end of the river between its north bank and the nearest pier of Hungerford Bridge which may now be seen at low water, covered with mud, and sending forth anything but agreeable or wholesome odours”.

“It is on this spot that I propose to place the grand Central Station, the site for it being formed by making a solid embankment of as much of this large area as may be necessary,” he added.

Christian Wolmar, the author of Cathedrals of Steam, a book about London’s great railway stations, said: “In the 1840s, there weren’t many stations that near the centre.

“They were all in places like Bishopsgate or Nine Elms or outside the centre, precisely because building into the centre was too expensive.”

The Stockton and Darlington railway was officially opened on 27 September 1825, making it the world’s first public steam-powered passenger railway.

An estimated 40,000 people witnessed the steam locomotive Locomotion No 1 pull the inaugural train.

The new railway connected coalmines to the port at Stockton and proved the practicality of steam trains for long-distance transport.