The last thing that really alarming news needs is an alarmist response. The British population is disturbed enough to hear that Islamist fanatics are hatching a plot to blow up nine transatlantic aircraft. What it does not need is to add to that a lot of hype - of the type much in evidence at the weekend - about "campus terrorists" and "moral blackmail".
Government ministers reacted with exasperation yesterday to the open letter signed by prominent Muslim MPs, peers and community leaders suggesting British foreign policy is placing British citizens in increased danger at home and abroad. To say that, ministers riposted, is tantamount to saying: "bomb us and we'll change our policy". That is true. Yet our Muslim leaders have come to the right conclusion, even if for the wrong reasons. British foreign policy should change, not from fear of terrorist reprisals, but because that policy is, in so many ways, wrong.
But the response of the Muslim community underscores a wider problem. Scepticism over what we have been told about the airport terror alert goes considerably wider than the Muslim community. It has not helped that the story, and the backroom briefing, has shifted. First we were told that the arrest of terrorist suspects was prompted by the imminence of the threat: the men had booked seats on US airlines for next Wednesday. Then it was claimed that the timing of the swoops was prompted by the arrest of one of the suspects in Pakistan. First we were told by the Home Secretary, John Reid, that all of the main players in the plot had been gathered in; next that a number of suspects remain at large. First that the Attorney General was concerned that Mr Reid's announcement had undermined the possibility of a fair trial; then that he was not.
So it went on. It has raised as many questions as it has answered. If police have been monitoring the plot for some time, how was it that the increased security arrangements at British airports were so hand-to-mouth? Blaming the incompetence of the airport authorities is no answer. The Prime Minister's decision to proceed with his holiday only deepens the mystery. Further suspicions were raised yesterday when Mr Reid revealed that the security services had foiled four other major plots since 7/7 - and an earlier one, in Birmingham, a year before 9/11 - and then used the opportunity to press once again for powers to detain terrorist suspects without trial to 90 days, a proposal which the House of Commons has recently, rightly, rejected.
The big question which sceptics are asking is who benefits from the current alarm. Messrs Blair and Bush do; they can now gesticulate to yet another point in their dot-to-dot arc of terrorism. Mr Reid does; already the bookies have shortened the odds on him standing against Gordon Brown for the Labour leadership. Mr Brown does too; the Treasury's decision to freeze the accounts of the arrested and publicise their names, underscores the Chancellor's tough-on-terrorism credentials.
Once the British public did not raise such a quizzical eyebrow. They took the view that their politicians were a phlegmatic bunch who routinely and unsensationally acted in the best interests of their citizens. But such goodwill has been spent by the dodgy dossier, the weapons of mass destruction ready in 45 minutes, the tanks at Heathrow, the innocent man shot dead on the London Tube, the Forest Gate fiasco and so forth.
It may well be that the plot to blow nine aircraft out of the sky was as well-advanced as has been suggested. If so we should, of course, be disturbed. But it is also alarming that, as things stand, so many people are not alarmed. The Government's previous cries of "Wolf" echo too loudly in the public's ears.