I have written about these limitations and studies about them several times before (see below). The best article arguing against the European missile shield is a May 2008 article by Theodore Postol and George Lewis in the Bulletin of the Atomic Scientists (free PDF here).
And as arms expert Pavel Podvig succinctly wrote in the Bulletin of the Atomic Scientists only three days back, it's not just about the technology, but it's about a fundamentally flawed concept:
"The fundamental problem with the argument is that missile defense will never live up to its expectations. Let me say that again: Missile defense will never make a shred of difference when it comes to its primary mission--protecting a country from the threat of a nuclear missile attack. That isn't to say that advanced sensors and interceptors someday won't be able to deal with sophisticated missiles and decoys. They probably will. But again, this won't overcome the fundamental challenge of keeping a nation safe against a nuclear threat, because it would take only a small probability of success to make such a threat credible while missile defense would need to offer absolute certainty of protection to truly be effective...It's understandable that people often talk about European missile defense as one of the ways in which to deal with the missile threat posed by Iran. Or that someday missile defense could provide insurance for nuclear disarmament--this is the vision that Ronald Reagan had. When framed in this way, missile defense seems like a promising way out of difficult situations. But this promise is false. If a real confrontation ever comes about (and let's hope it never happens), we quickly would find out that missile defense offers no meaningful protection whatsoever".Now the Obama administration has decided to scrap the unworkable shield and has decided to replace it with a much more realistic defense against short-range missiles. I cannot imagine how gratified this must make the scores of scientists, engineers and policy officials who have long argued against the feasibility of the shield. It also signals a huge shift in Bush-era foreign policy. Notice how the administration has diplomatically and shrewdly avoided mentioning the basic failures of the earlier system.
Unfortunately, the sordid history of missile defense and the inherent satisfaction that seems to stem by arguing in favor of a "shield" to protect the population makes me skeptical in believing that the concept is dead forever. But for now, there is peace in our time and this is a significant breakthrough.
Past posts on missile defense:
Made For Each Other
Missile Defense: The Eternal Bug
Holes in the Whole Enterprise
Czechs halt missile shield progress