Leading article: Less a global arc of extremism than proof of alienation closer to home

The idea that these people are motivated primarily by 'hatred of our freedom', as George Bush argued, is misleading

Yesterday we learnt the identities of some of the people suspected of plotting to bring down transatlantic passenger planes. The list is worthy of study. Almost all of those named are British Muslims, many with family links in Pakistan. Most were born in the late 1970s and 1980s. Those who committed the 7 July attacks on London last year came from a strikingly similar background. If it turns out that the two dozen people being questioned by the police were indeed plotting this dreadful crime, a portrait of a radicalised generation of British Muslims would seem to come into focus.

In the wake of the 11 September terrorist attacks on New York and Washington it was widely presumed that the threat to our societies came from outsiders. Security experts painted a picture of regional cells with direct links to al-Qa'ida. Yet the major terrorist threat today seems to be something very different. We see relatively small groups operating autonomously, creating explosives made from chemicals that can be easily acquired. These are cottage industries of terror, rather than the industrial-scale conspiracies we were led to expect. We also see British nationals, people who have lived in the UK all their lives, orchestrating these plots.

It is vital that we recognise this reality. For our success in thwarting these attacks will rest largely on an accurate analysis of the nature of the threat we face. First we must accept that this is a domestic problem. It cannot be blamed on outsiders. Sealing ourselves off from the rest of the world through tighter immigration controls would offer no real protection. There may indeed be international links, as the Pakistan connection in this latest case and also in the case of the 7 July bombers would suggest. But to talk up a seamless, global conspiracy stretching from Afghanistan to High Wycombe, as our Prime Minister has with his "arc of extremism", is dangerous. What we have here is a home-grown terrorist threat.

It is, of course, disturbing that people who were born and brought up in a free and prosperous society such as Britain are prepared to slaughter thousands of their compatriots to achieve their fanatical goals. The crucial question is: how they became so alienated from mainstream British life? Declining social mobility in Muslim communities has played its part. And as Tarique Ghaffur, Britain's most senior Asian police officer, has warned, government policies and police methods risk alienating young Muslims further.

But something even more potent has been added to this mix. The idea that these people are motivated primarily by "hatred of our freedom", as George Bush argued this week, is deeply misleading. The evidence, from the testimony that has come to light of two of the 7 July bombers, suggests that their primary motivation is actually a hatred, not so much of the West, but of Western foreign policy.

The Prime Minister is justified in pointing out that Islamist terrorism existed long before the invasion of Iraq. He is justified in pointing out that there can be no reasoning with individuals so warped that they would kill thousands of innocent people, including themselves, in pursuit of their ends. But he is not justified in implying that his own disastrous foreign policy has played no part in creating a new, intensified threat within our own borders.

In many ways, the danger we face today is the blow-back from the catastrophic "war on terror" to which Mr Blair has committed the United Kingdom. Our security services can - and must - continue to foil plots as they come to light. But unless we recognise this central truth, and do something to remedy it, the ranks of this generation of fanatics can only be expected to grow.