An effective defense against North Korean ICBMs is a legitimate and worthy policy goal, and the stakes involved in a nuclear attack are high enough to justify large investments and reasonable risks. Most would agree that the United States should have an effective defense against North Korean ICBMs without compromising strategic stability with Russia and China. But a rush to deployment would be misguided.
The existing homeland missile defense—the ground-based mid-course defense (GMD)—has many weaknesses. The GMD system is susceptible to simple countermeasures. It has not demonstrated high reliability in flight tests, and it has not been tested in realistic operational environments. The Missile Defense Agency (MDA) has adopted a plan to address these issues, but it needs time to implement these steps. Program managers in the DoD and external experts should be involved in evaluating whether a truly effective GMD missile defense system that stays ahead of the North Korean threat can be developed and deployed. A rushed deployment disrupts such efforts. The sensible course of action is to subject the GMD system to normal standards of testing while exploring additional options, such as the airborne boost-phase intercept (ABI) concept discussed below.