In a nearly barren apartment here, Najma Ramadan, 3, a curly-haired blonde wearing tiny bear-shaped earrings, climbed the walls one recent evening, from pipe to pipe. The little girl’s toys sat far away, in boxes in South Bend, Ind., where her father, Tariq Ramadan, was to have taken up residence in August as the Henry Luce professor of religion, conflict and peace building at the University of Notre Dame. Nine days before his family’s scheduled departure for the United States, Mr. Ramadan, 42, a Swiss theologian of Egyptian descent who is probably Europe’s best-known Muslim intellectual, received an urgent message from the American consul in Switzerland: Washington had just revoked the visa granted him after a security review last spring.Full Story