As we all know by now, that wasn't to be, thanks to a decision by US immigration in Los Angeles airport to refuse entry to Conroy, throw him in a cell for most of a day and then deport him. Conroy's crime was that on a previous visit to the US, he had overstayed his visa by 48 hours. In a deeply paranoid nation, a two-day overshoot on a 90-day visa is seen as a potential indicator of terrorist sympathies;

hence Conroy was treated with the kind of hostility experienced by an increasing number of travellers to the United States.

Morning Ireland tried to get to grip with US immigration policy during the week, interviewing a man from the embassy in Dublin who was, to his credit, honest enough not to leave us with any impression that he cared much about Conroy or anybody else in a similar situation. There is no flexibility in such situations, he said. Contact the embassy if you've overstayed your welcome in the past; they'll sort you out.

In years to come, Conroy can entertain his grandchildren with stories of how he suffered minor collateral damage in the "war against terrorism". If they are inquisitive folk, his grandchildren may wonder what kind of world we lived in in 2006, where one of granddad's crowning achievements as an actor was ruined by an immigration official who thought this Irish stranger may have been up to no good.

The United States, they will conclude, must have been a place of the tightest security, determined that under no circumstances should it be attacked again after the horrific events of 9/11.

And if they stop there, they might then conclude that what happened to granddad, what happened to John McCourt, the Dublin professor who was verbally abused, strip-searched and locked in prison overnight by US immigration officials in January, was probably the price that had to be paid for the extreme vigilance that kept terrorists from attacking America.

That is certainly the view of the US administration, which has been rounding up innocent people on a variety of suspicions and hunches for some time now. Eighty thousand Arab and Muslim men have been fingerprinted and registered over the last four years. Eight thousand Arabs and Muslims have been interviewed by the FBI; 5,000 foreigners have been "preventively detained"; many thousands more, and Ruaidhri Conroy now joins their number, were held on immigration charges, all in the name of the "war against terrorism".

Every year, 30,000 businesses receive demands from the FBI, "national security letters" as they are called, looking for confidential information about customers. The customers are not allowed to know that their details are being handed over.

And all that is before you even consider the madness of Guantanamo.

So what, some people will ask. We should support the US in its quest to ensure that it never suffers a 9/11 again. What are 80,000 fingerprinted Arabs, or a deeply disappointed Irish actor, compared to lives saved, terrorists captured, attacks against America avoided? We could argue that contention on human rights grounds alone, but let's deal with it purely in terms of results, of terrorists caught, of convictions secured in the courts. Let's investigate the success rate of US anti-terrorism strategy and see whether the detention of Ruaidhri Conroy and all those others can be explained away as the price of eternal vigilance or should more properly be described as the inevitable result of perennial paranoia.

The Bush administration claims that it has obtained more than 200 criminal convictions in relation to terrorism, but investigations by the Washington Post recently indicated only 39 of these cases were actually terroristrelated. Most of the rest involved immigration fraud, making false statements or other petty crimes. According to New York University last year, "the legal war in terror has yielded few visible results. There have been. . .

almost no convictions on charges reflecting dangerous crimes."

In a comprehensive examination of terrorism-related charges brought by the US authorities, which appeared in a recent issue of the New York Review Of Books (web address below), David Cole points out that for all America's aggressive prosecution of the "war against terrorism", not a single al-Qaeda cell has been discovered in the US. He reveals that of the aforementioned 80,000 who were fingerprinted, the 8,000 who were interviewed and the 5,000 who were detained, "not one stands convicted of a terrorist crime today. In what has surely been the most aggressive national campaign of ethnic profiling since World War II, the government's record is 0 for 93,000."

While aggressive tactics at home have proven next to useless in the "war against terrorism", the US also stands accused of doing very little in areas where it could achieve important results. According to a new book . . . The Next Attack by Daniel Benjamin and Steven Simon . . . the US is so obsessed with aggressive methods it has lost sight of important defensive actions that would be vastly more effective, such as securing nuclear and chemical plants, protecting water supplies and monitoring cargo at shipping ports.

In December, the 9/11 Commission graded the US administration on how it had dealt with more than 40 recommendations in the commission's investigation into the attacks on the twin towers. It awarded five Fs, 12 Ds, eight Cs and one A-. Amongst the Ds was one for identifying vulnerable targets, another for the government's efforts in securing weapons of mass destruction and another for screening luggage and cargo for explosives.

Whatever you think of Ruaidhri Conroy's experience last Sunday, you cannot argue that it was part of a package of measures that is detecting and convicting terrorists. Rather it was the action of a xenophobic and hostile nation, which week by week is further angering those who already hate it and losing the respect of those who used to love it. That's what the history books will tell Ruaidhri Conroy's grandchildren.