In my eyes, having a U.S. anti-ballistic missile system is now way to ensure security. They only encourage possible nuclear bombadiers to think of more cunning and ultimately lethal ways to deliver their payload.
That said, if the United States is going to pursue one, and never mind President Bush’s abrogation of the AMB treaty of 1972, it’s best to do it in a way that would note provoke our former hated opponent who happens to have 3,000+ nuclear missiles aimed at us. And vice versa.
Remembering this may help put things in perspective.