It further orders "a layered defense against larger and more sophisticated ballistic missile threats."

One of the crew's primary missions has been layered defense of foreign oil terminals critical to the local economy.

He would not be trapped by a layered defense this time.

Iraq has established a layered defense of the city and the United States has been methodically pushing through it.

But Israel insists that the checkpoints are a military necessity, part of the layered defenses needed to guard against Palestinian attacks.

The immune system protects organisms from infection with layered defenses of increasing specificity.

The department says it has created a layered defense that would not be compromised by the failure of a single device.

It's got to be a layered defense.

I've been told that the short-term plan is to get the whole brigade down here, arrayed in layered defense.

To what extent does the U.S. have a layered defense?