We’ve come a long way. Last time, the harassed Brazilian was shot dead

Progress takes many and mysterious forms, and the tendency in a land as determinedly nostalgic as ours is to refuse to recognise it as progress at all. Yet even the wearer of the rosiest-tinted glasses in the Specsavers autumn range must grudgingly concede that, in the field of terrorist suspicion-related policing of visitors from Brazil, things have improved remarkably in the last seven years.

Back in July of 2005, to be a Brazilian in transit in London was to send the enforcers of law and order a gilt-edged invitation to a state sponsored execution. Seven short summers after the Met whacked Jean Charles de Menezes on a Tube train for no apparent reason beyond its own staggering incompetence, the law-abiding Brazilian traveller with no conceivable link to terrorism may expect nothing worse than being hauled into a Heathrow interrogation cell, and questioned for the maximum nine hours permitted under the Terrorism Act 2000.

On Sunday, this is what befell one David Miranda, the partner in love and in work of Glenn Greenwald, the Guardian reporter who broke the story about the blanket digital surveillance deployed by the US National Security Agency, as revealed by Edward Snowden. Whether Mr Miranda appreciates how far the Met has come since it iced his compatriot is not yet entirely clear, but so far the churlish ingrate has failed to thank them for letting him return to Rio alive. Honestly, some people simply have no idea how lucky they are.

What Mr Miranda has revealed is that police confiscated and examined various items of electronic equipment, including not only computers and memory sticks but also a games console, and repeatedly threatened him with jail if he refused to co-operate. “They treated me like I was a criminal,” he said, “or someone about to attack the UK.” Since going without liquid for the first eight of the hours, until being allowed to buy himself a Coke, seems about as close to torture as it went, some may wish to dismiss this as fairly trivial.

It isn’t, of course. It is an abundant disgrace that British police officers detained and interrogated a foreign national they had not the slightest cause to suspect of any offence, let alone terrorism, in this predictably crude and cretinous manner. O brave new world – as an earlier Miranda almost put it in The Tempest – that has such dunces in it.

In fairness to the dunces, it must be observed that they were acting on instructions from the Home Office, or some other branch of the British state, which was in turn was doing the express or tacit bidding of the Americans, in the style boldly pioneered by Mr Tony Blair. We know this because a White House spokesman has confirmed receiving a “heads up” in advance of the incident (always good to see the courtesies being observed), and it is hard to imagine a PC, or even a desk sergeant, calling the Oval Office to declare: “Mr President? Constable Smith from the Met. We’re about to have a situation at Heathrow ...”

That feckless waste of space, the Independent Police Complaints Commission, will now waste a deal of time and effort on examining the matter, before confirming the Met’s own finding, after a long and searching internal enquiry, that “the use of the power in the case was legally and procedurally sound”.

No doubt it was. It would also be legally and procedurally sound to enforce the ancient law mandating all able bodied Englishmen to practice archery every Sunday, but that too might strike you as a criminal case of the police wasting their own time. What this is about, as if it needed stating, is a cynical misapplication of legislation to frighten Mr Greenwald and other journalists who may wish to exercise their professional and democratic right to report; and a brazen fishing expedition to unearth information lawfully contained within Mr Miranda’s equipment.

This is by no means the first instance of legislation intended for a dramatically different purpose being misused to intimidate the innocent, and pour discourager les autres. You may recall how Walter Wolfgang, the elderly concentration camp survivor, was bundled out of a Labour conference for heckling Jack Straw; and how Maya Evans, a devilishly menacing young vegan woman, was arrested for reciting the names of British troops killed in Iraq.

But the Miranda case is evidently the most sinister, and the result will be the precise reverse to the one the police – or rather those who asked them to perpetrate this idiocy – had in mind.

If journalists love one thing more than being martyred in the eyes of the world – if martyrdom isn’t too dramatic a term for becoming very mildly dehydrated – it is a full-frontal challenge to the lawful exercise of their trade. You bully newspapers at your own grave peril, and inevitably the scrutiny of covert surveillance by the American and British governments will now intensify. Mr Greenwald will report even more aggressively, he says, and hats off to him for that.

Obviously, this incident throws the nascent battle between paranoid governments and those duty bound to expose how they indulge the paranoia – a battle fast developing into destructive war – into its sharpest relief so far. But there are other issues raised, and these are as depressing to anyone with the desire to live in a decent, civilised, independent country as they are tiresomely over-familiar. The pitiful, unofficial 51st state sycophancy towards America one naively dreamed would fade with the passing of New Labour finds another form of expression. The post-9/11 authoritarianism, which we are supposed to regard as profoundly unBritish, grows more alarming. The politicisation of the police becomes ever more entrenched.

All of the above stem directly from 9/11, of course, or rather from the tragically misguided reaction to that monstrosity which saw the British government ape the Americans by abandoning paying even lip service to the paramount need to protect the liberties supposedly under threat from a global terrorist network. As so often in recent years, one can almost hear Osama Bin Laden cackling with glee from beyond his watery grave, as he sees his enemies stampeding like terrified bison into a trap he may not have been smart enough to have deliberately laid.

If there is a temptation, based on experience, to put the blame on the stupidity of the Metropolitan Police, it is worth resisting on better grounds than that, this time, no Brazilian died. They may be preternaturally useless in many regards. And since their commanding officers are entitled, if not obligated, to reject preposterous and immoral instructions, the Nuremberg defence cannot exonerate them.

But the IPCC should spare itself the bother and expense of faking a fearless investigation. All such a charade would achieve is to divert the spotlight from those, either in Government or “working towards the Führer” in the Government’s service, who shamed this country and ridiculed its values by giving the orders in the first place.