Is Al Qaeda Planning A Summer U.S. Strike?

The re-emergence of al Qaeda in a safe haven in Pakistan is driving the fear of a summer attack on the United States

Despite a six-year war on terror, al Qaeda is having renewed success in raising money and recruiting jihadists, reports CBS News correspondent Bob Orr. Numerous raw intelligence tips also say the terror organization has re-established a semblance of command and control with the ability to dispatch operatives.

"Well, they've been able to do it in the past, as far as moving people into Europe, into the U.K.," says CBS News terror analyst John Brennan. "I think the intelligence services have good intelligence that shows that al Qaeda has been able to move those operatives."

U.S. officials say they can't prove or disprove reports that a new al Qaeda cell is in the U.S. or on its way. That information from one source in Afghanistan is described as "suspect" and has not been corroborated.

But there are other troubling signs that something bad is brewing — the recent attacks on London and Glasgow, a deadly string of bombings in Northern Africa and a relentless propaganda campaign from al Qaeda, which officials fear represents a renewed confidence.

"All of this causes me in general to look at the summer as time when we have somewhat more risk and we need to be very vigilant," Homeland Security chief Michael Chertoff said.

Al Qaeda has a history of striking in summer months. The attack on America was launched in September, the British train bombings happened in July, and it was just last August when authorities uncovered a plot to blow up U.S.-bound airplanes.

"There has been no letdown in al Qaeda's determination to carry out an attack against the United States. We have slowed them, we have hurt them, we have damaged them, but we have not eliminated them," says Brennan.

But U.S. officials so far haven't connected any new dots. They say there's no evidence of an imminent attack, though they worry about what they don't know.