IkhwanOnline, the official Web site of Egypt’s Muslim Brotherhood, posted an article on Thursday asserting that the country’s new interim president, Adly Mansour, is secretly Jewish. The article, since taken offline,suggested that Mansour was part of an American and Israeli conspiracy to install Mohamed ElBaradei, a former U.N. official and Egyptian opposition figure, as president. Mansour, the supreme justice of Egypt’s Supreme Constitutional Court, was sworn in as interim president on Thursday after the military announced that President Mohamed Morsi was no longer in charge. Morsi was a close ally of the Muslim Brotherhood, which has held large demonstrations protesting...