Who the hell are you?

Fly to America and your most intimate details will be filed and passed to the intelligence services.

For at least the past 20 years, I have felt that civil liberties counted as a specialised interest, just like golf or architecture, which I didn't have to share. The phrase has none of the glamour or emotional charge of civil rights; indeed, it's right up there with "EU constitution" or "freedom of information" as one of those important but tedious terms that has me automatically flicking to the next article. In the west, surely all the arguments and most of the battles had already been won. I could leave it to groups such as Liberty to deal with the skirmishes.

But now and then something happens which makes you realise the world you think you live in is not the solid, reliable construction you imagined. For me, it was not Guantanamo - appalling as it was, I assumed that this indifference to established norms was a limited phenomenon that wouldn't reach into ordinary lives. What made me uneasy was a relatively minor revelation.

It was the discovery that European airlines flying to America have been compelled to give the US government free access to all the details they hold on every one of their passengers. Not only does that include names, addresses, nationality, passport numbers, credit card details and addresses while in America, but it can include any other information on the airlines' databases, such as medical information, disabilities, special meals ordered, price paid, onward flights, past itineraries, banking details and names of persons to be contacted in emergencies. In short, if you have flown to, from or through America in the past two years, then key elements of your life, including quite possibly your ethnic and religious identities, are being held on file by the American authorities as part of their worldwide information-gathering. They are sifting and analysing that data to see whether you pose a threat to them, or whether they think you may do so in the future.

Once the next stage of their passenger-profiling system is in place, which is planned for next year, each of us will be allocated a colour coding. Greens will be free to travel. Yellows, a category thought likely to include Arabs or foreign Muslims, will be considered a security risk. They will get extra-intensive screening, and may be fingerprinted and photographed. Red will mean that you are on a terrorist watch list, and you will be detained by airport security.

This system, known as Capps II (Computer-Assisted Passenger Pre-screening System II), is not confined to foreigners. All Americans who fly will be entered on it, and their files will be available to other government departments. Yellow-coded files could also be shared with the CIA and with foreign intelligence agencies. Capps II will be the basis for a comprehensive tracking and surveillance system of everybody who moves in America. The American Civil Liberties Union fears that it will evolve into a totalitarian system of internal controls, affecting political dissenters, as well as supposed terrorist threats.

In Europe, data protection laws allow information to be used only for the purpose for which it is collected. America has no such laws. The EU is arguing with America over how to restrict its access to the passenger records of European airlines, but from a position of extreme weakness. America says it will fine air- lines $6,000 per passenger if they fail to provide all the access demanded, and the EU's transport commissioner says he cannot afford to bring air traffic with America to a complete halt.

The potential scope of the system was revealed in August, when it was discovered that a low-cost airline, JetBlue, had given information on its 1.1 million passengers to a private US army contractor, despite promising passengers that the information was confidential. The contractor cross-referenced the data with social security files, occupations and the economic files held on commercially available databases, it came up with passenger risk profiles, and the results were presented at a Department of Homeland Security seminar.

Can the system be justified by the threat to America, and by its focus and efficiency? Not on the evidence so far. Capps II is not yet in operation, but its precursor clearly is. Earlier this year, many Americans discovered that they were being prevented from boarding flights, or were subject to continued and mystifying searches and security measures. A nun from Milwaukee, who had no criminal record and had never been arrested, was prevented from catching a plane to Washington for an anti-war protest. Two female peace activists wanting to fly from San Francisco to Boston for a family visit were detained for hours by security police. A left-wing constitutional lawyer was repeatedly strip-searched before flights. A law-abiding computer software engineer who flies twice a week (and happens to share the same name as a detainee at Guantanamo) found himself repeatedly delayed, searched and questioned every time he checked in. All these people, and many others, it turned out, were being stopped because they featured on the Transportation Security Administration's "no-fly" lists. There is no mechanism for finding out why names are listed, nor for removing them. After several meetings with the TSA, the only solution the software engineer was offered was to change his name.

Many more names are going to appear on those no-fly lists in future. Last month, the Bush administration announced that it intends to combine the records of a dozen federal agencies to make a master "watch list" of more than 100,000 terrorist suspects - so that there can be no repeat of the intelligence confusions that led to the 11 September 2001 attacks. But how accurate will the lists be? How will they be used? And what is the definition of terror? Officials are frank about the last. It will be wide, and will include, for example, Americans suspected of involvement in domestic events, such as attacks on abortion clinics. Inclusion on that list will have far-reaching consequences. Private employers such as power plants and airlines will be allowed to use it to make secret checks on potential employees. Again, there is no mechanism to discover or challenge inclusion, and no right of appeal against capricious judgements. Michael Ratner, of the Centre for Constitutional Rights, says it recalls the blacklists of the McCarthy era. It challenges the whole basis of America's laws, which is that people must be allowed to test the accusations made against them.

Among Americans, there are some stirrings of unease. In the immediate aftermath of 9/11, there was no public outrage at the largely random "preventive detentions" of almost 800 immigrants in the New York area. People simply disappeared from their homes, could not be traced by their relatives, were denied legal help, and were deported months later, mostly for minor immigration violations, after being mistreated and beaten in prison. Not one was ever charged with any terrorist offence. There was no reaction, either, to the government's closing of some courts to the public during immigration and terrorism trials. Judges issued sombre warnings. One said bleakly of his secret court: "Democracy dies behind closed doors." But he wasn't reflecting the public mood. In autumn 2001, Congress passed the Patriot Act by a huge majority, allowing unprecedented surveillance and searching of anyone whom the security services defined as being of interest. Only one senator voted against it. The assumption was that, in the war on terror, new tactics were justified.

Now ordinary people fall under suspicion for ordinary behaviour. In San Francisco, a retired phone company worker got into a fierce discussion at his gym about the failings of President Bush and the war on Iraq. He was woken several days later by federal agents calling at his apartment to interrogate him about his politics. Last February, a middle-aged defence lawyer in New Mexico was in an internet chatroom when he apparently suggested that "Bush is out of control". Within hours, he was surrounded by police, then handcuffed by Secret Service agents and questioned about whether he was a threat to the president. In North Carolina, a 19-year-old was visited by FBI agents who had been told she had "un-American material" in her apartment. It consisted of a poster opposing Bush's use of the death penalty. She was asked what she knew about the Taliban and questioned for 40 minutes. Her details have been placed on file.

Gradually, Americans have woken up to the idea that it is not just terrorists and foreigners who are potential targets of the Patriot Act, and that they too may have something to fear from it. So far, 160 cities and towns and three states have passed resolutions opposing it. It removes many constraints on the security services' powers. Agents no longer need to demonstrate to an independent judge that there are good reasons to suspect an individual of terrorist or criminal activity. Instead, they take their requests for search warrants to a specially constituted intelligence court, which has never yet turned down an application from the FBI. Agents need only claim they are investigating a threat to the state.

But the definition covers many legal activities. In the case of a non-citizen, a letter to the local newspaper criticising America's foreign policy is now enough to trigger an investigation. And that investigation can extend far beyond the suspect. If he or she has used someone else's computer, it may be seized; if he or she has e-mailed an organisation or a contact, that account, too, can be bugged. The agencies can secretly read or seize records of any kind, including confidential medical, business and banking records. Phones can be tapped, e-mails duplicated and websites monitored, without any meaningful judicial supervision. Under what have been termed the "sneak and peek" provisions, any home or office can be secretly searched without your being notified until weeks or months later.

Yet it isn't these measures that have aroused most public anxiety - it is the government's new power to track, secretly, what people read, research and borrow in public libraries. For the past two years, many libraries have had wall signs warning patrons that the library cannot guarantee their privacy, and may be required to hand information on them over to the FBI.

Much of the anger at this has come not from urban liberals, but from conservative rural communities. Robert Reich, who was labour secretary to President Clinton, told me that the library issue has united ordinary people, libertarians and civil liberties activists. "It's become symbolic of the entire effort to watch us," says Reich. "There's something very personal about library books, and it's too close to George Orwell and the behaviour of totalitarian governments. Americans guard their privacy with a tremendous sense of righteousness and indignation. We hate big government. This country was founded on a suspicion of it."

The library issue has become so emotive that the government has been forced to respond. Last month, the US attorney general, John Ashcroft, went on a nationwide tour, in front of carefully selected audiences, to defend the Patriot Act and to make the case for further extensions of it. Exasperated by the libraries question, he finally declared information he had refused to give to Congress, and said the powers had never yet been used. But no one knew whether or not to believe him. The libraries' own survey, a year earlier, had shown that at least 178 libraries had been visited by the FBI. And no librarian could publicly confirm or challenge what Ashcroft claimed, because, as with all the subpoenas served under the Patriot Act, it is illegal for the recipient ever to reveal that they have received or complied with one.

As 11 September 2001 recedes and doubts grow over the Iraq war, a divergence is emerging between the powers the government seeks and those the public and the legislators are prepared to let it have. Recent government proposals have been so outrageous that the US Senate has made clear that it will never support them. Senators were appalled when, as part of a proposed new act termed Patriot II, Ashcroft sought the power to strip citizenship from any naturalised American suspected of aiding terrorism - a provision that could apply to anyone who was, say, offering advice on peace negotiations to the Turkish Kurds. This summer, too, the Senate voted to block further funding for several pieces of legislation, including sneak-and-peek. And when the Department of Justice suggested the creation of a mass spying programme, which would have turned ten million Americans into informers on their friends and neighbours, it was rejected by Congress without a dissenting voice.

But the administration isn't reining back; far from it. On the anniversary of 11 September, George Bush claimed that "unreasonable obstacles" in the law were impeding the pursuit of terror suspects, and said the hands of law-enforcement officials must be untied. He wants an expansion of the death penalty, and even fewer judicial restraints on the police and security services. Fearful of rejection if he puts forward a single bill - Patriot II - the measures are likely to be attached piecemeal to other bills, in the hope they will pass on the back of less contentious legislation.

The government's opponents argue that its tactics are wrong, and that instead of carelessly creating new powers, it should have used existing ones more effectively. After all, the 11 September hijackers were spotted; it's just that the intelligence was not acted upon. What is needed is a more focused approach, not a loose and expanding one. Robert Reich points out that it is far from clear that intruding on civil liberties is an efficient way of finding terrorists. Even with all the resources available, the anthrax terrorist has not been found. Reich argues that the current strategy will merely generate huge quantities of useless information on so many people that it will be unusable.

Liberals and libertarians are nowhere near winning the argument. Only 22 per cent of Americans think too many civil liberties have been lost; there is also little sympathy for the civil rights of foreigners, or of undocumented immigrants. It is the civil liberties of mainstream America that are of potential concern to the nation, not those of anybody else. The price of that, as Reich says, is that America loses something incalculable - the moral high ground, the right to assume any kind of leadership and the chance to win the sympathies of those it is busy detaining and expelling.

Some observers think the current situation is cyclical. In the 1940s, there was a panic in which civil rights were removed from Japanese Americans; in the 1950s, McCarthyism; in the 1970s, attacks on the anti-war movement. Each time, the country went into a spasm and then came to its senses. But others are less sanguine. In this electronic era, the intrusive power that can be wielded by governments is so great that one cannot be confident that it will disappear. Michael Ratner warns that it will be hard for people to regain the liberties they have lost. And Reich says we should all worry about the reaction when another outrage takes place. What liberties will be demanded and surrendered then?

What does this mean for us in Britain? What happens in America influences the way our politicians think, and the context in which we react. ID cards, national databases, the tracking of internet and phone use, files on children: these all look almost reasonable compared with America's readiness to create files on all its citizens. But we can see which way the government's intentions are going, and it should be resisted. We can see from the Hutton inquiry how ferocious the state can be when someone gets in its way - and how powerless officials can be, even when they are attempting to do the right thing and protect our interests. We should not casually surrender more authority, knowledge or power to that machine.

A month after 9/11, an American judge, Andrew Napolitano, wrote in the New Jersey Law Journal: "In a democracy, personal liberties are rarely diminished overnight. Rather, they are lost gradually, by acts of well-meaning people, with good intentions, amid public approval. But the subtle loss of freedom is never recognised until the crisis is over and we look back in horror. And then it is too late."

It seems to me it is no longer enough to leave the defence of our freedoms to the pressure groups.