Nonetheless, to the extent that terrorists have come into our country or suspected or known terrorists have entered our country across a border, it's been across the Canadian border. There are real issues there.

Such a system would be very, very expensive and laborious to have, given the kinds of border we have. Scientists and engineers aren't even sure they have the technology to make it work

But my view is that you need a system at the border. You need some fencing but you need technology. You need boots on the ground. And then you need to have interior enforcement of our nation's immigration laws inside the country. And that means dealing with the employers who still consistently hire illegal labor.

And we ask the American people to play an important part of our layered defense. We ask for cooperation, patience and a commitment to vigilance in the face of a determined enemy.

Now, a lot of what we are doing right now, quite frankly, is because of what happened on Christmas. Many of the things were kind of in the works. We were already planning, for example, the purchase and deployment of advanced imaging technology. You call them body scanners. We call them AITs (Advanced Imaging Technologies).

As part of our layered approach, we have expedited the deployment of new Advanced Imaging Technology (AIT) units to help detect concealed metallic and non-metallic threats on passengers. These machines are now in use at airports nationwide, and the vast majority of travelers say they prefer this technology to alternative screening measures.

If American schooling is inadequate now, just imagine how much more obsolete it will be when today's kindergarten students graduate from high school in just 12 years.