History helps, now and then.

 One piece of the historical record says that the United Kingdom should not be too pious over the "harsh" or "intensive" American methods used in the interrogation of terrorist suspects. Sensational documents from the Senate add nothing to knowledge. After all, Britain invented most of those techniques.

Sleep deprivation? Stress positions? Naked people subjected - with no irony understood - to terror in another war on terror? People in British uniforms and Whitehall suits did those things, and more, in Kenya, the Gulf, the North of Ireland, and Iraq. Then in places never mentioned. Then we exported our expertise. It made us valued allies, from time to time.

We forgot to mention the obvious, of course, to our friends at the CIA in Langley, Virginia, and elsewhere. It doesn't work. Those who survive just hate you a little more. Those who die become martyrs for the cause you mean to extinguish. The "intelligence" gained is essentially worthless. People in extreme pain will say anything you like.

That's part of what is meant by being "held to a higher standard". Moral superiority is nice. Being less stupid than a Dick Cheney or a George W Bush is a practical advantage if you mean to keep people safe. But employing techniques that serve only to justify the rhetoric of psychopaths condemns you to the intellectual aridity of a TV mini-series.

Our leaders, mostly elected, can't resist. They exist in the kind of moral desert John Wayne would have called home. Their purpose, in their war on terror, was never to add to knowledge, but simply - sometimes grotesquely - to inflict pain on an enemy. Yet if the Senate Intelligence Committee is to be believed, not one piece of "life-saving" information was retrieved by America - and 52 other allies - by wallowing in torture.

Barack Obama has used the word. His rivals maintain that his honesty renders him weak. Call a thing for what it is, say those voices, and you give comfort to this year's eternal enemy. A true democracy does not strip a body from a mind, it merely employs "enhanced" techniques and lots of fine speeches. America does not torture; it just gets tough with the enemies of freedom.

In the late summer of 1971, Britain did a lot of torturing. At Girdwood, at Magilligan, at Ballykinker: nice places, mostly. It was not a happy time for the North of Ireland, however, or for Britain. And armed republicanism in these islands did not disappear because 342 individuals were bagged up. You might say instead - as we appear to have forgotten to mention to the CIA - that matters were made worse.

The claim runs that "we" don't do these things. On the watch of Mr Bush, many lawyers spent a good deal of time attempting to establish that no US law, or any version of international law, was breached by waterboarding, or sleep deprivation. The UK, with a near-fantastic capacity for dissimulation, has simply pretended, year after year, Labour or Tory, that "officially" we knew nothing, did still less, but accepted the fruits of "intelligence".

The vastly-redacted Senate report has raised another issue. Crudely, these are crimes. In anyone's version of law, international and foreign, the treatment of prisoners - nowhere denied - is beyond the pale. Simply to remind the world that terrorists don't care about due process won't do. Torture was allowed, endorsed, "indicated", indulged and accepted. Nothing in American or English law, civil or military, allows that.

Arrests then? But who are we kidding? One of the dullest jokes in the free western world rests on the fact that Mr Bush, Tony Blair and all the rest will never face interrogation, far less a risk to liberty, for debauching democracy. The worms are a sight bigger than the can. Being "held to a higher standard" has come to mean not being held to any standard. Among struggling countries, this is noticed.

The fact remains: we - or our friends and allies - did not hesitate for an instant over the use of torture. The essence of the argument is surely that we offer something better than the nihilism of terrorism and suicide belts. We don't behead people. We don't threaten their children. We don't tell them how they must think and feel. We don't bully. We believe in rights.

When legal action is brought in the US and UK against the agents of torture, I might manage another noble paragraph. The great corruption embraced by Mr Bush and his kind was exactly this. This was what they seemed always to want. Finding an enemy with a face, hurting that enemy, eradicating that enemy, seemed to matter more than the obvious: "How come we would up with so many enemies?"

The US did not not earn its woes. Little Britain's empire is long gone. But if we engage in or indulge torture we are not entitled - legally or morally - to set any of the rules. That's a problem. For America, it's a bigger deal than America yet seems to grasp.

If the republic is not a moral exemplar, what is it, exactly? Just a negotiable currency? Just the biggest armed force on the block? Just this year's movie? America - as Mr Obama is fond of saying - is an idea. And America does not torture human beings.

But it does. That being so, the rest of us might have to grasp that the American century is long done, that Mr Obama isn't knee-high to Franklin Roosevelt, that most of the planet has no interest in Ronald Reagan's shining city on a hill, and that a torture state is a just a torture state. These are hellish truths. Mr Obama could probably send a killer drone to confirm them: that's the problem.

When moral authority disappears, the rest is epilogue. The election of that first black President was supposed to change all. Shutting down Guantanamo was promised as his first executive act. No one, even his enemies, suggests that the US has continued to torture prisoners on his watch. But still. "One nation. Under God. With liberty and justice for all." The frank truth is that a big part of the planet no longer believes any part of the oath. It too is history.

That's not fair, of course. But the "controversy" over a censored Senate report is more revealing, almost, than the report itself. It speaks to the republic's uneasy sense that the world is watching now, that brave stories and ugly darkness make an obvious contrast, that the heroic movies no longer work. Or this: if America tortures, what hinders the rest?

We'll hear more of that, soon. Britain's easy imperial cynicism was said to lend licence, in decades past, to all varieties of state power. The US still likes to think of itself as better. But when you begin to say that telling the ugly truth is a "security risk", you have lost every argument.

For our freedom's sake, agents of the United States did hideous things to people never convicted of a crime. Your employees helped. That's not how this is supposed to work.