The Missile Defense Agency is scheduled to test its Ground-based Midcourse Defense (GMD) interceptor over the Pacific later this month. The test target it will be directed against is being designed to mimic an Iranian long-range missile attack on U.S. territory.
This test is a valuable undertaking and will serve to educate the Missile Defense Agency and others in the U.S. government about important aspects of what is required to defend U.S. territory against such an attack. What the test will not reveal, however, is the extra level of protection that would be afforded to U.S. territory against Iran by fielding GMD interceptors in Poland, as well as the United States, under the Bush Administration’s “third site” plan. President Obama cancelled this third site option last September.
Unfortunately, the Missile Defense Agency has never been precise in public about the advantages gained for protecting U.S. territory against Iranian long-range missiles from the third site deployment compared to relying solely on U.S.-based GMD interceptors. This goes back to the Bush Administration. To be sure, the Missile Defense Agency pointed out that the third site interceptors would protect both Europe and the United States against such missiles. Further, it has acknowledged that the existing interceptors in Alaska and California, absent the third site interceptors, can provide coverage of U.S. territory against the same threat. Nevertheless, it is fair to state that the Missile Defense Agency saw clear advantages for defending U.S. territory in going forward with the third site option. At least, the Missile Defense Agency said so at the time it was proposed. The third site proposal was never about defending just Europe.
Accordingly, the outcome of this test should not be viewed in a vacuum. Whether the GMD interceptor successfully downs its target in this test will provide only a partial answer to the question of how well defended U.S. territory is and will be against an Iranian long-range missile attack. What policy makers need to determine, as well, is the extent to which an increased in the number and geographic distribution of GMD interceptor deployments will increase the chances of success in countering an Iranian attack.