A staggering wave of coordinated bombings and attacks swept across 15 Iraqi cities on Monday, killing more than 100 people.
Although there was no immediate claim of responsibility, the leader of al-Qaeda in Iraq announced this weekend that the group was launching a new offensive. Correspondent Jane Arraf says the attacks demonstrate al-Qaeda's durability.
"The sheer scope of it was staggering," Arraf says. "This was really a wake-up call for a lot of people."
Arraf says many Iraqis fear a return to sectarian strife.
"After everything it took to drive back al-Qaeda, when the Sunni tribes aligned with American forces and fought against al-Qaeda …it could be slipping backwards again and they could be re-emerging."