R. Jeffrey Smith in the New York Times:
Griffin was referring to a revolutionary new type of weapon, one that would have the unprecedented ability to maneuver and then to strike almost any target in the world within a matter of minutes. Capable of traveling at more than 15 times the speed of sound, hypersonic missiles arrive at their targets in a blinding, destructive flash, before any sonic booms or other meaningful warning. So far, there are no surefire defenses. Fast, effective, precise and unstoppable — these are rare but highly desired characteristics on the modern battlefield. And the missiles are being developed not only by the United States but also by China, Russia and other countries.
Griffin is now the chief evangelist in Washington for hypersonics, and so far he has run into few political or financial roadblocks.