It may not be much consolation to the thousands of Britons who are beginning their holidays with interminable waits at airports or phoning from home to learn whether their flights will ever depart, but they are playing an important part in the campaign against terrorism. The disruption they are suffering results from the frustration of a plot which, if what we are being told is even halfway correct, could have dwarfed the horror of 9/11, let alone the attacks which followed, including the bombings in London, Madrid, Istanbul and Bali.
For this is where the "war on terror" is truly being fought - not in Iraq, still less in Lebanon, but in meticulous police and intelligence work. It is unusual for the struggle to surface in such a public way, but if the allegations concerning the threat to transatlantic airliners are proved, it will be a testament to thousands of hours of unseen work in intercepting electronic messages and money transfers, surveillance of suspects and seeking information from members of the public who do not share the terrorists' distorted views of "justified" targets, "legitimate" revenge, and a clash of civilisations. It is a complex, difficult task, requiring international co-operation and trust between governments who do not always agree in public.
In this light, the words of Tony Blair to an audience in Los Angeles earlier this month, before he went on holiday, seem all the more curious. The Whitehall spin machine was at pains to point out that the Prime Minister never used the phrase "war on terror"; instead he was even more apocalyptic, talking of "a war ... not just against terrorism but about how the world should govern itself in the early 21st century, about global values". This "elemental struggle" was in part between "Reactionary Islam and Moderate, Mainstream Islam [his capitals]". Hence Afghanistan, hence Iraq, he went on.
As we have already pointed out, Mr Blair seemed to be confirming the view of Islamist extremists that the struggle against terrorism was one against Islam; that we went into Iraq and Afghanistan not merely to change a regime but their "values". Worse, in the context of Lebanon in particular, it reinforces the belief that the best - indeed, almost the only - way to fight terror is by military means. In the past few days, Muslim leaders in Britain have again complained that British foreign policy is helping to draw disaffected young Muslims towards extremism, and the Government has again responded with a flat denial and the suggestion that any such complaint comes close to justifying terrorism.
So once again, let us repeat: there is no excuse for acts of terror of the sort that appears to have been averted last week. The argument is about how to defeat terrorism. Many experienced professionals on both sides of the Atlantic have argued in the past that it would be more useful to treat al-Qa'ida and its allies as an international criminal conspiracy, akin to the Mafia or drugs traffickers. They argue that the "war on terror" accepts the movement at its own evaluation, as a visionary army seeking to create a Muslim Caliphate across the world. While the analogy should not be stretched too far, the implication is that resources should be devoted to the real struggle - the one being carried out by MI5, the police and other security agencies in this country and abroad - rather than being squandered on foreign battlefields.
The other aspect of the Government's standard response to such criticism is that Islamist extremists were plotting and carrying out acts of terrorism long before Iraq, Chechnya or any other conflict in which Muslims are involved. To which, not for the first time, our answer is that we should be concentrating on the real enemy, which is al-Qa'ida and its offshoots, rather than engaging in a foreign policy which not only diverts time and attention from the real struggle, but furnishes our adversaries with recruits.