Leading article: The terror is not over

It made last month's downgrading of the threat assessment from "critical" to "severe general" look curious. If the security services were unable to make a connection between Khan and al-Qa'ida until al-Qa'ida did it for them, it does not inspire confidence that they know more than the rest of us. Yet the video does add important layers to our understanding of the threat. It is clearer now that the London bombers were not simply a group of deluded young men acting on their own. It is apparent that while al-Qa'ida, whose spokesman Ayman al-Zawahiri was spliced on to the same video, may not possess a tightly organised military structure, it suggests a degree of planning and calculation in playing on public fears.

The response to the video, too, was significant. There were few voices suggesting that it should not be broadcast. This was in contrast to the demands for censorship of Osama bin Laden's crowing over the 2001 attacks on America. And it poses an awkward question for the Government's planned law to ban the glorifying of terrorism, which is precisely what Khan's video does. More sensible to show the video so that, in the Prime Minister's words, the ideology that lies behind suicide jihadism can be challenged. So that the absurdity of accusing the British of "gassing" Muslims can be exposed. So that the poison of presenting Afghanistan, Chechnya and Kashmir as a single "war" against Muslims can be drawn. So that it can be pointed out that, in Iraq, al-Qa'ida is killing Shias for being the wrong sort of Muslim.

Many Muslims in this country have responded to the video with commendable clarity. The determination of Gous Ali, the boyfriend of Neetu Jain, a Hindu killed on the Tavistock Square bus, was particularly impressive: "As a Muslim, I will spend the rest of my life confronting these people. As a Muslim, I will fight for this country, because this is my country and I am loyal to it." Let us hope that the titular leaders of the Muslim faith in Britain will speak with a comparable lack of ambiguity.