Quantifying Counterforce and Active Defense in Countering Theater Ballistic Missiles

Abstract

This paper contains the formulation and analysis of a model to measure, compare, and contrast the effects of counterforce (pre-launch attack) and active defense (post-launch attack) against tactical ballistic missiles (TBM's). It is shown that without counterforce an active defense system could require an impractical number of weapons to counter incoming missiles and/or their warheads. This number is shown to decrease geometrically as effective counterforce is used, so that the expected number of warheads killed increases dramatically with counterforce that is only modestly effective. Actual distributions of warheads reaching the target area are shown to be complex mixtures of binomial distributions. It is shown that normal approximations to these distributions based on the easily-calculated means and variances often agree poorly with the actual distributions. This is especially true when using effective counterforce.