Lying behind Ms Verdonk's decision are two changes in the Dutch mood since fears over the compatibility of Islam and liberal democracy reached a peak in 2004.

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For instance, by a 2-to-1 margin, people who describe themselves as conservative Republicans have a more negative view of Islam than do those calling themselves liberal Democrats.

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Ms Hirsi Ali is a Somali refugee who has made a career in Dutch politics by standing against radical Islam and defending her adopted homeland's liberal values.

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And in Germany, as everywhere in Europe (see Charlemagne), the challenge posed by immigration and political Islam is forcing people to think about the axioms a liberal democracy must uphold.

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For liberal-minded Muslims, the old split between Dar al-Islam (the realm of Islam) and Dar al-Harb (the realm of war) hardly applies to an era in which some of the happiest adherents of their faith live as minorities.

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Mr Wilders's party is only one of many anti-immigrant and anti-Islam groups that are gaining ground in northern European countries previously known for their liberal social attitudes.

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Moreover, both Turkey (which Mr Laqueur mostly traduces) and the Arab spring (which he barely mentions) suggest that reform and liberal democracy can, albeit with difficulties and arguments along the way, be made compatible with Islam.

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Around that time Mrs Erdogan, friends say, converted from Shafi'ism (an orthodox version of Sunni Islam which forbids all physical contact between men and women unless they are married) to the more liberal Hanafi school, followed by most Turks, so she could shake hands with men and non-Muslim women.

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