The latest dispute is in Switzerland, which is planning a nationwide referendum to ban minarets on mosques. This month, Italy's interior minister vowed to close a controversial mosque in Milan.

Some analysts call the mosque conflicts the manifestation of a growing fear that Muslims aren't assimilating, don't accept Western values and pose a threat to security. "It's a visible symbol of anti-Muslim feelings in Europe," says Danièle Joly, director of the Center for Research in Ethnic Relations at the University of Warwick in England. "It's part of an Islamophobia. Europeans feel threatened." ...