The new Egyptian Prime Minister Essam Sharaf denied any responsibility; instead he blamed "hidden hands". Such conspiracy theories have long been used by the authorities to stoke up hostility towards America and Israel. Since the military regime took power some 12,000 people have been arrested, forced to confess (often under torture) and convicted by courts martial, using draconian emergency powers. The scale of this repression dwarfs that of Mubarak, as Islamist influence grows. For Coptic Christians the future looks bleak. Iraq has lost nine-tenths of its 2.5 million Christians in ten years; the Copts, the largest remaining religious minority in the Middle East, look isolated and exposed.

Across the world, at least 100 million Christians live under persecution, three-quarters of all victims of bigotry. Many thousands are killed every year, mainly by state-sponsored violence; indeed, it is likely that more have died for their faith in the last century than in the previous 19 put together. Yet The Better Angels of Our Nature, a much-lauded new study of "The Decline of Violence in History and its Causes" by the cognitive psychologist Steven Pinker, manages to overlook this persecution altogether. The churches too have been all but silent. Pope Benedict has been more outspoken than his predecessors, but Christian minorities are hostages.

For Christians in the West who care about their co-religionists in the East, it is excruciating to watch them endure the terrible fate that Jews have suffered (often at the hands of Christians) for so long. It may, however, be salutary. The cause of freedom of conscience is a noble one, in which Christians, Jews and secularists have a common interest. The Arab spring must not be allowed to degenerate into one huge pogrom from Tripoli to Tehran.