Before an international audience, Dr. Sugar addressed how the development of a missile-defense capability can change the "calculus of proliferation." In his address he examined three important aspects of missile defense:

On the diplomatic front, a layered capability provides leverage to "dissuade, defend and add value to deterrence," Dr. Sugar said.

It helps to remove an aggressor's ability to hold democratic nations hostage, split alliances or deter a response to regional dangers.

"We need multiple intercept opportunities against all ranges of missile threats in every phase of flight," Dr. Sugar said.

"A layered approach drives the probabilities so greatly in our favor as to complicate the job of any enemy."

He added that international attention must now be turned to building and deploying a boost phase shoot-down capability, now that mid-course defenses are moving forward.

"The US Missile Defense Agency is currently looking at two technologies. One is directed energy weapons - lasers - carried aboard aircraft. The other is a system of hyper-velocity rockets that catch up to enemy missiles soon after launch. Both systems are complementary, providing layers within layers," Sugar said.

Dr. Sugar said the new boost-phase capability is the defense community's opportunity to move toward internationalization of missile defense, at both the industry and government level.

"Our hope is that cooperation at the industry level will encourage increasing participation on the part of other governments, moving toward a new regime of 'mutually assured protection."