“The reason for concentrating on them,” the al-Qaeda leader explained to his top lieutenant, “is that Obama is the head of infidelity and killing him automatically will make [Vice President] Biden take over the presidency. . . . Biden is totally unprepared for that post, which will lead the U.S. into a crisis. As for Petraeus, he is the man of the hour . . . and killing him would alter the war’s path” in Afghanistan.