While there will be certainly be much more said on this site about the recent National Academy of Sciences Report on “Making Sense of Ballistic Missile Defense,” here I just want to briefly comment on a somewhat remarkable  figure provided by the NAS via (the National Research Council ) to the New York Times.  The figure, shown below, appears on the Times website here. 

While I understand the point this figure is trying to make, about the advantage of having multiple intercept opportunities, it nonetheless shows only one of four intercept attempts against an incoming missile succeeding.  The remarkable thing is that, based on the evidence to date, a one-out-of–four success rate is exactly right.  Here are the results of the last eight intercept tests of the U.S. national Missile Defense System, in which the incoming warhead was killed only twice: