In the immediate aftermath of the September 11, 2001, atrocities, reports of the detention of senior al-Qaeda operatives abroad were greeted with relief, the raising of the terror-alert level was treated with consider-able respect, and arrests of suspected extremists in Britain were, subject to the due process of law, deemed to reflect well on the authorities’ efforts. But three years after the assaults on New York and Washington, it has become fashionable to dismiss the campaign against terrorism with scepticism, if not outright cynicism. It is suggested by some Democrats that the discovery of the most wanted al-Qaeda members is a matter of political scheduling to assist the Bush re-election effort and that threat-alert levels are being deliberately manipulated.

Similar assumptions have been expressed in Britain where cynicism about the US has itself reached record levels. The passing of time will reveal whether the arrests made in London, Blackburn, Bushey and Luton will prove significant. They have, though, been denounced as part of an Anglo-American conspiracy. Massoud Shadjareh, the chairman of the Islamic Human Rights Commission, contended yesterday that his organisation was “extremely concerned” about their timing because they came “the day before the parliamentary human rights group publishes their report, which is critical of the Terrorism Act and the treatment of the Belmarsh prisoners”. His assertion echoed the weary sentiment of John Humphrys on the Today programme when inquiring of the new US terror alert: “What is it this time?”

What it is this time is what it has been for almost three years. The US and British governments remain engaged in a long and complicated struggle against terrorism. The notion that the intelligence services in Pakistan, or elsewhere, twiddle their thumbs and await the most electorally helpful moment at which to grab a major al-Qaeda leader is absurd. The criticism initially made of the decision to raise the terror alert in America — that it was a suspiciously disproportionate response to material that was two or three years old — was itself simplistic. Recent information on fresh al-Qaeda activity also played a role in this decision. And it is ludicrous to imagine David Blunkett, the Home Secretary, ordering arrests to overshadow a parliamentary committee’s report.

In a sense, Mr Blunkett and Tom Ridge, the US Homeland Security Secretary, are victims of success. Because there have been no attacks in the United States or Britain over the past three years, some individuals and organisations have concluded that there has never been any prospect of such an event occurring and that politicians are striving to keep the War on Terror in business for their own ends. Those who were or are detained at Guantanamo Bay have been elevated to the status of virtual martyrs in certain quarters, their seizure in Afghan war zones notwithstanding. It is right to insist on due process and to condemn abuse, but it is not the moment to be naive or nice about potential terrorism.

It is too early to repeal such provisions and it is wrong to wallow in self-indulgent cynicism about the drive against terrorism. The authorities do have moral and legal responsibilities. In a presidential election year, there is a special burden on the Homeland Security Department to outline as many of the reasons as is practical for why a higher level of terror alert has been deemed appropriate. Mr Blunkett has to demonstrate to independent figures why it is necessary to intern foreign nationals in a British prison indefinitely. A strategy based on pre-emptive arrests and a rapid and public reaction to changing intelligence is the right one. It should not be undermined by destructive scepticism. Would the cynics be convinced if we got tough only after the fact?