On the subject of the unassuming hairdresser from Oldham, Mohammed Sajid Khan and his diminutive but charming wife Shasta Khan much more remains to be said.

Mr and Mrs Khan hold the dubious record of being Britain's first married couple to be convicted of terrorist offences. At Manchester Crown Court she was given an eight-year sentence as a reward for having planned to blow up Jews.

He had previously had the grace to own up to preparing sundry acts of terrorism, and is serving an indefinite jail term. It is easy - too easy - to dismiss the Khans as Islamists and their murderous intentions as isolated and untypical. Islamist, yes. Isolated and untypical? I wonder.

Two things struck me about the coverage of the trial and convictions. The first was that there was much less coverage than it deserved. This story - of the deliberate identification of Jewish targets in Manchester and of the planned murder of British Jews by fellow citizens - was hardly accorded the status of headline news. But even amongst those outlets that did run it the focus was on the "how" rather then the "why". We were told how the Khans devised their plot to acquire the ingredients to construct a "viable explosive". We had it confirmed that the couple had also taken to "driving around Jewish communities in the Manchester area looking at possible targets".

But why were they so engaged? Det Ch Supt Anthony Mole was honest enough to admit "the overwhelming evidence suggests they were in the attack-planning stage of a terrorist act motivated by antisemitic beliefs". But, pointing out that the North West Counter-Terrorism Unit had "found no evidence to suggest this couple were collaborating with anyone else," he concluded that "there is nothing to suggest any residual threat to our communities".

It is easy — too easy — to dismiss the Khans as untypical

I beg to differ. I believe there is a "residual threat" to Jewish communities throughout the British Isles and that even if the Khans were acting alone they nonetheless went about their activities within a value-framework that has gained substantial and frightening credibility in the UK. And within this framework it has become fashionable to denigrate, denounce and delegitimise Jews and Judaism - to say nothing of the Jewish state. And I further believe that successive governments have been remarkably complicit in bringing about this state of affairs.

As the Khans were beginning their sentences, a friend showed me a Ramadan appeal leaflet that had been pushed through his London letterbox. "Barely a day goes by," it insisted, "without news of fresh Palestinian casualties. Facing increasing oppression and hardship, the great majority of the Palestinian population lives in total poverty - with no access to clean water, proper healthcare and education and the skills and means to earn a decent living."

Even if we forgive as artistic licence the assertion that "barely a day" passes without "fresh news of Palestinian casualties", to claim that "the great majority" live "in total poverty" strikes me as a wild exaggeration (if not a downright lie) bordering on incitement. But I doubt very much that anything will be done about this leaflet or those who distributed it.

But it's not just the unbridled, racially-motivated anti-Zionism of Islamists and their fellow travellers that I have in mind. "I'm not anti-Jewish," an academic colleague told me during a recent conference, "but I think shechitah should be banned." In support of this contention he referred me to a speech delivered by Farming Minister James Paice last June, in which he described kosher slaughter as "wholly unacceptable".

When a minister of the crown sees fit to condemn in these terms what Shechita UK rightly described as "a cornerstone of the Jewish faith", is it any wonder that anti-Jewish prejudice is becoming respectable? And when, from Downing Street, there comes not one word of rebuke, should any of us be surprised that this newly-rediscovered respectability is justified in terms of its perceived endorsement at the highest levels?

Attacks on Jewish religious practices are attacks on Jews. And anti-Zionism is almost always racist in intent and effect.