'Sleeper Cells' Awake In London?

(CBS)  An American terrorism expert says evidence shows so-called sleeper cells have been quietly plotting attacks like the ones that hit London Thursday, and that other cities across Western Europe might be vulnerable as well.

CBS News consultant, Col. Randy Larsen, director of the Homeland Security Institute, told co-anchor Rene Syler on The Early Show Thursday that he'd just read a report about "how Islamic terrorists are throughout Western Europe.

"Several times, we've discussed here, do we have sleeper cells in the U.S.? We think so, but we're never sure.

"But over 300 Islamic terrorists have been arrested in Europe since the '93 attack on the World Trade Center, many of them in the London area.

"Shortly after 9-11, they arrested some folks there who were making a sarin bomb, a type of nerve agent. They arrested people trying to build a dirty bomb. Just last year, they captured a ton of fertilizer in a warehouse that was going to be used to make a very large bomb, similar to what Timothy McVeigh used in Oklahoma City in 1995.

"So, there's no question that there's a large terrorist operation in London. And I think we see the result of that (Thursday). … It's clear it has all the earmarks of an al Qaeda attack."

Larsen noted that communications capabilities in the Washington, D.C., area have been improved since 9/11 to assure that "first responders" to attacks are able to use their cell phones.

But he says he learned in a trip to Scotland Yard after 9-11 that a key factor in fighting terrorism is to get things back to normal as soon as possible after an attack. Another key, he was told, is for affected areas to be resilient.

"We must not magnify the effects of these attacks," Larsen stressed. "We must not let the terrorist disrupt our lives."

He added, "A couple months before the attacks on the trains in Madrid, al Qaeda said that they were going to try to influence Spain's involvement in Iraq. And so, we must not respond to the terrorists in the way they want. So get things running (again in London) quickly."

Larsen says he wasn't "at all" surprised when he heard about the attacks: "We have been talking for quite awhile that a likely scenario was an attack on a subway system. It's an ideal place for a terrorist to plan one, and also doing it in a city like London, which is so dependent …London cannot operate without its subways and buses."

He also pointed out that, "Al Qaeda is a completely different organization than it was on 9-11. It's very fractured and splintered now. They have people who were trained by al Qaeda and received some funding and some logistical support, but it's pretty much up to those individuals operating in (different cities) to decide where and when to have attacks. It's a much different operation today.

"The way these folks work, they can go the logistics planning, to get the equipment they need and do the surveillance. Al Qaeda-trained people do a tremendous amount of surveillance to find the right targets, the right time of day or whatever. But then, you can put all those plans and equipment on the shelf, and then with one phone call, in as little as 24 hours, execute those plans."