The terrorist news that caused me to spend the weekend hiding under the blankets was not Dame Eliza Manningham-Buller's warning that MI5 knows of at least 30 ongoing plots, but the threats from both major parties to create a cabinet "terror supremo". Gordon Brown says that, as prime minister, he would take personal charge of our security. David Cameron is calling for a "minister for terror".This prospect should make us tremble. A minister with dedicated responsibility for national security would be justly resented by all the cabinet colleagues on whose corns he or she would trample. And whereas the present home secretary spends only half his time devising ill-considered and often pernicious legislation to protect us, a "terror supremo" would do nothing else.
International terrorism, overwhelmingly promoted by Muslim extremists, represents a long-term threat to western democracies. It will get worse before it gets better, by which time most of us will be dead, hopefully of natural causes. The means by which the threat can be diminished - let us not pretend that it can be removed - impinge upon every corner of government and society.
We have learned a lot since 9/11. George Bush, abetted by Tony Blair, resolved that terrorists must be hunted down in their supposed breeding and training grounds, in Afghanistan (true) and Iraq (false). Neither military engagement has proved an unqualified success. Pakistan's radicals pose a grave threat, but even the Washington neo-conservatives do not now propose committing troops against them. The most plausible lesson of recent experiences is that it is counter-productive to deploy large-scale western military forces in Muslim societies, even where there seem just grounds for doing so.
Diplomacy, persuasion, covert intelligence, bribery - in cash or kind - will henceforward become the principal tools for addressing terror abroad, as they should have been all along. Within western nations, more effective scrutiny of borders is hard to achieve, but seems essential. Britain's intelligence services are now getting lots of money. Their problem is to absorb a flood of raw recruits who face a steep learning curve before becoming effective.
I am not one of those who believes that conventional wars have been abolished, and thus that the British army can dispense with its tanks and artillery. But in the next generation, the intelligence services, police and special forces will hold the keys to national security.
Yet when all this has been said, our most intractable problem is not one of law enforcement, but of tensions within society. Many of the threats identified by MI5 are not the handiwork of foreigners, but involve British citizens. Most of us are acutely dismayed by opinion polls appearing to show that a significant Muslim minority sympathises with last year's London bombers, and, indeed, with al-Qaida.
We are threatened by a cycle of mutual hostility. The inevitable response of many white people to Muslim radicalism is increased suspicion of immigrant communities, which in turn deepens their own sense of alienation.
A book published this year, The New East End by Geoff Dench, Kate Gavron and Michael Young, examines the social and economic condition of Tower Hamlets in London. It focuses chiefly on relations between the large Bangladeshi community and the white working class. It vividly depicts the fears and anger of white people, founded in a perception that new immigrants are exploiting the welfare state and public housing much more successfully than the area's old occupants.
The book's language is temperate, but its conclusions are bleak. "One of the unintended consequences of extending citizenship to migrants from former countries of the empire," the authors say, "surely lies in the way that it has strengthened the legitimacy of greater emphasis on citizens' rights without working to create a national culture of responsibility, mutuality and solidarity."
They cite the widely held view among local white residents that "the whole moral order had become inverted by the emphasis placed by the state on individual need. For if what one gets out of the state is determined by need, rather than by what one has put into it, then dignity has gone out of citizenship. Dependency is encouraged, the principle of reciprocity has gone."
An intelligence service briefing paper on radicalism among young Muslims speculates that one reason home-grown militancy is more acute here than in the US is that the British welfare system renders it unnecessary for immigrants to seek integration into our society, while in America, if you don't join in and get work, you starve.
The government's idiotic response to the acquittal of two British National party leaders on race-hate charges was to say that it is considering strengthening the law. In truth, of course, the only rational answer is to address the causes of white working-class hostility to immigrants.
The New East End vividly makes the point that most white middle-class residents, like New Labour policy makers, adopt impeccably liberal attitudes to newcomers, because they do not live beside them. However, as long as the white working class believes that immigrants are favoured, and those same newcomers feel able to adopt the attitudes of mere economic campers in our society, Britain's race relations will remain pretty dire.
Terrorism is unmentioned in the Dench-Gavron-Young book. But it is obvious that the forces that create mutual alienation in Tower Hamlets are also at work in many other places, and threaten to yield violent fruits among the young.
Many of us remain baffled by one factor: throughout history, every society has spawned some disaffected people. Some have vented their grievances through violent assaults on the institutions and leaders of the state. Very few, however, have sought to inflict indiscriminate mass death on ordinary people.
It is not flippant to suggest that Islamist terrorists would inspire less public apprehension if they confined their murderous designs to politicians, policemen, soldiers and judges, as did the IRA and Italy's Red Brigades. We are roused by the fact that al-Qaida's followers hate our entire society so much that they refuse to recognise innocents or noncombatants deserving of mercy. Public fear is more intense than in the past, because all of us perceive ourselves as prospective victims.
It is hard to imagine any of these issues being better addressed by a cabinet terror supremo than by the existing machinery of government. Ministers could do much to improve community relations, partly through more effective control of immigration and an imaginative review of the welfare system. We shall know that we are getting somewhere in countering the terrorist threat when opinion polls show that almost the entire population of Britain - there will always be a few lunatics - perceive themselves on the same side in the struggle, as at present they do not. We will always have to live with imported terrorist atrocities, carried out by foreigners. We shall sleep easier in our beds, however, when we have achieved sufficient social harmony to relinquish our fears of enemies within.
Max Hastings