In the 52nd chapter of his ''Decline and Fall of the Roman Empire,'' Edward Gibbon posed one of the great counterfactual questions of history. If the French had failed to defeat an invading Muslim army at the Battle of Poitiers in A.D. 732, would all of Western Europe have succumbed to Islam?
''Perhaps,'' speculated Gibbon with his inimitable irony, ''the interpretation of the Koran would now be taught in the schools of Oxford, and her pulpits might demonstrate to a circumcised people the sanctity and truth of the revelation of Mahomet.''
When those words were published in 1788, the idea of a Muslim Oxford could scarcely have seemed more fanciful. The last Muslim forces had been driven from Spain in 1492; the Ottoman advance through Eastern Europe had been decisively halted at the gates of Vienna in 1683.
Today, however, the idea seems somewhat less risible. The French historian Alain Besancon is one of a number of European intellectuals who detect a significant threat to the continent's traditional Christian culture. The Egyptian-born writer Bat Yeor has for some years referred to the rise of a new ''Eurabia'' that is hostile in equal measure to the United States and Israel. Two years ago, Pat Buchanan published an apocalyptic book titled ''The Death of the West,'' prophesying that declining European fertility and immigration from Muslim countries could turn ''the cradle of Western civilization'' into ''its grave.''
Read the entire article on the New York Times Magazine website.