Paul Berman, in the New Republic, reviews Silenced: How Apostasy and Blasphemy Codes Are Choking Freedom Worldwide by Paul Marshall and Nina Shea.

It is a disturbing book showing how Islam is being corrupted by an aggressive and intolerant ideology.

The late Abdurrahman Wahid, once President of Indonesia, described radical Islamist political and terrorism as the product of an “extreme and perverse ideology.”

This ideology, as Berman notes, contrasts with

other, more tolerant and traditional currents of thought within Islam, more compatible with modern liberal ideas—such as the peaceable Sufism endorsed by Wahid, together with sundry humanist currents that descend from Islam’s medieval Golden Age.

Yet it is the radical Islamists who are making the political running in Islamic societies worldwide.

They wage a campaign of violence and intimidation whose most high-profile events were gruesome – the hacking to death of Vincent van Gogh on an Amsterdam street, the murder of Salman Rushdie’s Japanese translator.

But less high profile victims (Christians in Egypt, Somalia and Algeria, for example) abound, and the campaign’s success is partly the silence in which less spectacular events pass us by:

Incidents in which artistic or intellectual presentations have been cancelled without any accompanying violence or arrests have become fairly common: the sandblasting by the Dutch police of a mural in Amsterdam protesting the murder of van Gogh; the removal of artwork from London’s Whitechapel Gallery in 2006; the cancellation of a display at the Tate Gallery; the cancellation in Geneva in 1993 of a production of Voltaire’s play Fanaticism: or Mahomet the Prophet (followed, a dozen years later, by a minor riot when Voltaire’s play did receive a French production); the quiet removal of artworks from display by the Metropolitan Museum in New York in 2010 (though I wonder how Marshall and Shea would judge the Met’s ambitious new wing of Islamic art); the removal in 2009 of the Danish cartoons from a scholarly Yale University Press book about the Danish cartoons; the cancellation in 2009 of a German mystery novel about Muslim honor killings; the flight underground of a threatened cartoonist, Molly Norris, of the Seattle Weekly; the decision by eight hundred newspapers in the United States not to run a syndicated cartoon by Wiley Miller. And so on.

 Meanwhile, campaigns against “hate speech” and “Islamophobia” proliferate, often based on quaint paranoia about Western intentions:

 The doctrine postulates a conspiracy theory, according to which Crusaders and Zionists have been plotting to annihilate Islam for many hundreds of years—in the case of the Zionists, ever since the Medina controversies of the seventh century.

 The legal systems of the West have been instrumentalized to silence Islamism’s critics. Geert Wilders in Holland and Mark Steyn in Canada are well-known Western victims of these bizarre and shameful prosecutions, but many more are from Muslim backgrounds:

 the Anglican bishop Michael Nazir-Ali, who converted to Christianity; the brave and morally precise Italian-Egyptian journalist Magdi Allam, who also converted (at the hands of the pope, no less, such that his middle name is now Cristiano); the writer and activist Ayaan Hirsi Ali in Holland, until she left Holland; Necla Kelek, a German feminist from Turkey; Ekin Deligöz, a German Green politician from Turkey; Souad Sbai, the head of Italy’s Association of Moroccan Women, and too many others to list.

 Finally, perhaps most fatally, the campaign is leading to self-censorship of a kind which cannot bear even to acknowledge itself – a literally self-effacing cowardice.