But since this particular strain is expressed using the symbols of Islamic culture and Muslims’ identity, resisting it needs politics of exceptional subtlety.
Immigrants to the UK must not use safe harbour here to threaten or undermine our allies in the Middle East.
Their ideology dictates that such a person commands their political allegiance. And now ISIS has produced one.
The brouhaha that disrupted Queen’s Speech Day had more to do with personality than policy – as so often is the case.
The new Egyptian President had already neutered the Muslim Brotherhood. Now he faces much worse: Salafism, crime and instability.
Schools must be required to emphasise British values such as freedom of speech, freedom of religion, equality under the law – for Muslim and non Muslim alike.
What is crucial, and what the Government’s review will ascertain, is the relationship between the organisation and violent extremism.
They lack what Lenin called a vanguard of committed full time revolutionaries willing to brave death to transform their society, as Edmund Burke put it, “upon a theory.”
We should learn from being wrong-footed over developments in a country crucial to the fortunes of the wider middle east.
We should not be shy about defending human rights there. But for the country to fall into the hands of jihadist-sheltering Islamists doesn’t bear thinking about.