Al Qaeda , in contrast , had been in existence for a decade before it recruited its first affiliate , Egypt 's Jihad Group , in 1998 . Peter Bergen : More and more terrorist and insurgent groups are swearing loyalty to ISIS . In past six months , ISIS has attracted about a dozen groups , he says . The Associated Press contributed to this report.
Peter Bergen : More and more terrorist and insurgent groups are swearing loyalty to ISIS . In past six months , ISIS has attracted about a dozen groups , he says . The Associated Press contributed to this report.