He asserts that even if a missile interceptor succeeded in effecting a boost-phase "kill" on an incoming missile (that is during the early stage of its trajectory when it is moving relatively slowly, easily identified and vulnerable to destruction), its warhead might continue on and land in friendly territory with devastating effect.
It is the only place on earth where, under the anti-ballistic missile treaty, the United States was allowed to test its strategic interceptor missiles, a key component of President Bush's missile-defence programme, sometimes known as Star Wars II.
That proposed phase includes development of the SM-3II B interceptor, an advanced version of the missile currently provided aboard our Aegis missile defense warships.
One reason is that the Obama administration is rethinking a planned missile-defence system, which would have placed ten interceptor rockets in Poland and a radar station in the Czech Republic, in order to guard against Iranian missile attacks on America and much of Europe.
He has now also delayed funding for ground-based interceptor and radar sites in Poland and the Czech Republic for defense against Iranian missile launchers.