Hizb-ut-Tahrir — meaning Liberation Party — is so egregiously biogoted that it has been banned three times from university campuses by the National Union of Students. This ban was reaffirmed only last week — not an easy feat for an Islamist group in this culturally sensitive epoch.

The party was founded as an offshoot of the Muslim Brotherhood in the Jordanian-occupied West Bank in 1953. It believes in the necessity of a clash of civilisations between the West and Islam. It hates democracy and all laws and systems created by unbelievers. Its online history of this country is called Britain: Masters of Colonialism.

It is proscribed in Germany, Jordan, Kuwait and Pakistan, among others. No wonder: it believes in the overthrow of governments across the Muslim world on the ground that they are insufficiently “Islamic”, and their replacement by a borderless caliphate. The Bangladeshi government is but the latest target of Hizb ire.

Banning HuT might therefore have been supposed to be wholly uncontroversial outside the ranks of radical Islamists. But even after 7/7 this step has not proven to be easy — despite Tony Blair’s express wish last August to see the group cast beyond the pale. Indeed, the case of HuT casts a fascinating light on the impediments standing in the way of any government that seeks to protect its citizens.

Predictably enough, the Labour Left is in there, kicking up a fuss. Clare Short recently gave HuT a platform in the Commons to fight proscription — even though Article 108 of its constitution declares “the primary role of a woman is that of a wife and a mother” and that females cannot be senior judges nor live with foreign men.

Don’t expect balance from the BBC, either. When three Britons imprisoned in Egypt on charges of HuT membership were recently released, Today gave two of the detainees almost five minutes to spew out loathing of Mr Blair with only a nugatory challenge from James Naughtie.

The Association of Chief Police Officers also frets about a ban, fearing it will drive HuT underground. Acpo argues that it will be hard to justify proscription when the group claims to be non-violent political organisation. This is to misunderstand HuT. Its role has never been to perpetrate violence here. That would not be in its interest, since London is its nerve centre. HuT’s cadres have, rather, planted the seeds that are harvested much later by others: for instance, the 9/11 hijackers were lectured to by the HuT chief in Germany and were regular readers of HuT literature.

As observed by Zeyno Baran, a leading authority on HuT, the organisation acts as a “revolving door” into other even more extreme groups, such as its now defunct breakaway, alMuhajiroun. Above all, HuT can claim a measure of credit for shifting the terms of the debate within Islamism towards globalisation of the umma, or the Muslim nation: the notion that if one part feels pain, all others must respond accordingly.

Nor should Acpo fear overmuch about HuT being driven underground by proscription: it already operates underground in many areas and have been known to employ different names on those campuses from which it has been excluded.

Anyhow, the experience of the authorities in Germany suggests that the measure has been quite successful — sending a signal to those on the borderline of radicalism that this groupuscule is unacceptable. The costs of inaction are at least as great as those of action, however blunt an instrument proscription may be.

Above all, the debate on how to handle HuT casts a sharp light on Whitehall’s greatest weakness — the war of ideas. I once talked to a senior Northern Ireland Office mandarin about the revised school curriculum in New York: the Irish famine would now be taught as a deliberate act of genocide on a par with the Holocaust. If only one in a thousand young American minds were poisoned by this, what would that mean for the long-term stability of Northern Ireland, I inquired? If so, what would he be doing about it? The Sir Humphrey figure told me that the British State nowadays neither could nor should rebut such outrageous claims: that was not its job.

This approach seems to be dangerously unambitious — in both the Northern Irish and the Islamist contexts. Mr Blair well understands the importance of Islamist ideology, as exemplified by his remarkable speech at the Foreign Policy Centre last month. But can the Prime Minister get the system as a whole to put administrative flesh on these bones?

During the Cold War, organisations such as the Information Research Department of the Foreign Office would assert the superiority of the West over its totalitarian rivals. And magazines such as Encounter did hand-to-hand combat with Soviet fellow travellers. For any kind of truly moderate Islam to flourish, we need first to recapture our own self-confidence. At the moment, the extremists largely have the field to themselves.

Dean Godson is research director of the Policy Exchange think-tank

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