13 years after 9/11, are we safer?

Thirteen years after the terror attacks on September 11, 2001 claimed nearly 3,000 American lives, the group responsible for those attacks, al Qaeda, is a shadow of its former self, analysts say - but that doesn't mean the U.S. can afford to rest easy, given a host of emerging threats ready to take up the jihadist banner.

Even as the U.S. has battered al Qaeda's core, killing 9/11 mastermind Osama bin Laden in Pakistan in 2011 and keeping the heat on the group with drone strikes and other military operations across the near-East, the United States faces what some would label "more dangerous and more diverse threats than in the past," explained CBS News Senior National Security Analyst Juan Zarate.

"What you have is a reality of a metastasized global jihadi movement, with al Qaeda core, in many ways, diminished," Zarate said. "The group that was led by bin Laden that existed with the Taliban in Afghanistan [is] not playing such a prominent role but the other groups [are] playing a more prominent role."

Zarate mentioned al Qaeda's affiliate in the Arabian Peninsula, which continues to threaten the U.S., and the al Shabaab movement in East Africa, which was responsible for last year's deadly attack on a shopping mall in Kenya. That group was dealt a heavy blow last week when a U.S. strike took out its leader.

He also cited the rise of extremists in North African countries like Libya and Nigerian militants with Boko Haram, the group responsible for kidnapping hundreds of schoolgirls earlier this year.

"And of course the 800-pound gorilla now, [ISIS], which has established a foot hold in the heart of the Middle East," Zarate added, referring to the jihadists calling themselves the Islamic State who seized broad swaths of territory in Iraq and Syria throughout the year and recently executed two American journalists.

"This is a more complicated environment now than ever before," Zarate said.

Part of the danger, Zarate said, stems from the fact that the threat isn't as organized or as hierarchical as it was before 9/11, and it's coming from more actors.

"You have these groups that have found a way of developing locally, sometimes embedding in local insurgencies like al Qaeda in the Arabian Peninsula or al Shabaab. The Islamic State starts to look like a quasi-army or insurgency, but they also have cells that are focused on the west," he said. "You've got all these global hot spots, all of these groups that can do real damage in an age of globalization, when all you really need are a couple of guys with clean passports, and with a little bit of training, they can do some real damage."

And it's important to remember, Zarate said, that the "jihadi DNA" of these groups focuses not just "on the local fight, but also on trying to attack the United States."

One distinction between the current threat environment and the pre-9/11 environment that has policymakers worried is the number of westerners who have recently joined the jihadi cause. Al Qaeda was never too adept at recruiting foreign fighters to its cause, but the FBI estimates that over 100 Americans (and thousands of Europeans) have enlisted in the fight in Iraq and Syria on behalf of ISIS. And if those individuals can't be tracked, the danger is that they could eventually return home, radicalized by their experience abroad, to attack their home countries.

"The ideology and the narrative that al Qaeda spun not only animates these groups and ties them in a variety of ways, but also is animating independent actors, the lone wolves, and the actors in the west and drawing them to these fights and potentially drawing them back to attack their home countries," Zarate explained.

"This is a real problem, because the movement is gaining momentum in terms of the ideology...we have a challenge in the narrative that is animating a lot of these individuals and these groups."

Given the array of possible dangers, Zarate said he would hesitate to describe the overall threat level today as higher than it was before 9/11, but he said it's certainly "more complex."

"I'm not sure I would say it's greater, In part because I think we have better counter terrorism architecture both in the United States and around the world to deal with these problems," he said.

But "the reality is we're still blind in very dangerous corners of the world like Syria, and that makes it feel a bit like September 10, 2001," he warned. "And you're going to start hearing more and more politicians, counter-terrorism officials around the world talk about that fear that we're facing a threat that we may not see yet but that may come to bite us at home."