ALBUQUERQUE — It's not just the possibility of terrorists using nuclear weapons that worries Al Romig; it's the possibility of their using laptops that keeps him up at night.

Romig, senior vice president at Sandia National Laboratories, said Tuesday that cyberthreats are emerging as a serious terrorism threat. While it might be difficult to smuggle in a nuclear weapon, the only barrier to a cyberattack could be whether someone has a laptop.

For example, he said, a coordinated attack on part of the U.S. technology network that brought down a quarter of the nation's power grid and kept it down for a couple of weeks would have a huge economic impact.

Romig, Sandia's deputy director for integrated technologies and systems, opened a three-day conference here on "Terrorism: Threats and the Role of Technology." Sessions are covering everything from the roots of terrorism and various terrorist groups to terrorists' use of various weapons.

One of the first security problems Sandia worked on for the U.S. Department of Energy was the idea that someone could blow up a major dam and flood cities downstream. It turned out it's not easy to blow up a dam, but if someone took over the cybersystems that operate the dam and opened the gates, "it's just about as good," Romig said.

He outlined technology Sandia has developed in the area of homeland security: sensors at subways; walk-through detectors at airports; handheld explosives detectors; decontamination foams; ways to determine the source of biological agents; and instruments that not only detect radioactivity, but also what type to separate the benign from the dangerous and not mistake the mild natural radioactive potassium in bananas for the plutonium in a smuggled nuclear weapon.

"There are no silver bullets that will automatically just fix the problem," Romig said. "There isn't some magic law that we can pass. There isn't some magic box that a place like Sandia can create to fix the problem. ... It's really a systems solution that we require."

That means anticipating a rogue state or a terrorist group might do something nefarious; deciding how real the threat is — the likelihood of its happening and its consequences; using sensors and detectors to intercept the threat before it enters the country; diffusing it if it does get in; and recovering from an attack if one comes off.

It's also important to figure out who attacked and why, Romig said. "Not only to exact revenge ... but the fact that you can actually figure out who did it is part of the deterrent," he said.

It's difficult to disrupt scattered terrorist groups because they're different from a small state. Romig compared them to a Pillsbury dough boy — "press on one place, it squeezes out in another."

"They don't have the same vulnerability we have in a complex society like we have here," he said. "They're very dispersed, very loosely organized. When something happens somewhere, it's really not clear whether it's part of some planned act that perhaps was triggered by Osama bin Laden or some other fairly senior leader in the overall terrorist network, or it could be just a small cell that believes they are somehow morally connected to that movement."

A coordinated attack by "a bunch of satchel bombs in a bunch of shopping malls the Friday after Thanksgiving" would cause an economic ripple that could drive the United States into a recession, Romig said.

Still, he said, terrorists cannot destroy the United States.

"They can cause a lot of destruction, they can kill a lot of people, but they don't have the power to collapse the country," he said. "You've got to keep that in context."