An example might be an airborne laser, which is a project designed to put a laser on a Boeing 747 aircraft and shoot down missiles from the sky. That's designed as a theater missile defense, but depending on how it is deployed, it may also be able to protect the United States. In the past, the Pentagon has not been able to test it in that role because it would violate the ABM treaty. And under that system, they might be able to deploy some very limited defenses earlier, perhaps before the end of President Bush's term in 2004. And in some cases, they argue, it would be worse than having nothing at all because it would require the United States to walk away from the ABM treaty, alienate its allies, antagonize its adversaries such as China and Russia, while at the same time providing almost no real defense against missiles.
Critics argue that that is the worst of all worlds.
But the Pentagon counters that even a scarecrow that doesn't really have any potential to harm the crows can accomplish something if it keeps the crows out of the cornfield. And by the same token, they argue that even a limited defense, if it makes a potential adversary pause or think twice before attacking the United States, then it would have some deterrent effect. And if it has a deterrent effect, that is really the ultimate aim of a missile defense. It's not to win a war with missiles, but to convince the other side that it's not really in their interest to attack the United States. Defense Secretary Donald Rumsfeld didn't discount the idea of the so-called scarecrow option or scarecrow missile defense.