Israel's "Iron Dome" missile defense has been spectacularly successful at intercepting short-range Hamas rockets: officials relate that roughly 80-90 percent of attempted intercepts have succeeded. However, it is important not to learn the wrong lesson from this. Some have gone so far as to claim that Iron Dome's success finally vindicates Reagan's dream of a missile defense "shield" against nuclear-tipped ICBMs. That this small battlefield system has been so successful against the relatively slow-moving short-range rockets doesn't mean that larger and much more expensive missile defense systems, such as the planned NATO system, will work against longer-range strategic missiles that move ten times as fast.
Besides the speed of the quarry, there are two important distinctions between the systems: where the intercepts take place (in the atmosphere for Iron Dome vs. in space for the NATO system), and the nature of threat (conventional battlefield weapons vs. nuclear-tipped deterrent arms).
According to the current NATO missile-defense plan, the United States, working with European allies, would ramp up the deployment of a mix of increasingly sophisticated sea- and land-based missile interceptors around Europe in an attempt to guard against any possible future Iranian nuclear missiles. While this certainly sounds good, the problem is that an enemy intent on delivering a nuclear payload could easily defeat the NATO system by using decoy warheads, thereby swamping the defense's radars and other sensors with fake signals.
In contrast to the short-range Hamas rockets, which fly through the atmosphere during their whole trajectory, the longer-range ballistic missiles -- which the NATO missile defense system is designed to counter -- spend most of their flight in space. For decades it has been known that trying to intercept a warhead in space is exceedingly difficult because the adversary can use simple, lightweight countermeasures to fool the defensive system.
For instance, cheap inflatable balloon decoys -- similar to the shiny ones at children's birthday parties -- can be released together with the warhead when the missile burns out. Because the NATO missile-defense interceptors try to strike the warhead in the vacuum of space, these balloons and the warhead travel together, making it impossible to distinguish the decoys from the real thing. If many such lightweight balloons were released near the warhead, the defense would quickly be overwhelmed with fake targets.
In fact, the CIA's own top specialist in strategic nuclear programs testified in 2000 that "[m]any countries, such as North Korea [and] Iran ... probably would rely initially on readily available technology ... to develop penetration aids and countermeasures. These countries could develop countermeasures based on these technologies by the time they flight test their missiles."
Unfortunately, warnings of such fatal weaknesses were not heeded in designing the NATO missile defense system. Now, two government-sponsored scientific studies have shown that the missile defense system being planned to protect the United States and Europe is fundamentally flawed and will not work under combat conditions. As Philip Coyle, who was associate director for national security and international affairs in the Obama administration's Office of Science and Technology Policy, recently put it, the program is "chasing scientific dead ends, unworkable concepts and a flawed overall architecture."