The goal of the US ballistic missile defense is defend against a limited ICBM attack and regional missile threats. US ballistic missile defense program can't

The goal of the US ballistic missile defense is defend against a limited ICBM attack and regional missile threats. US ballistic missile defense program can't defend against large scale Russian attack. Defending against large scale attack has never been the goal of the program, nor is it a realistic goal. Russians use the US BMDS it partly as an excuse. Russians can easily compensate against any BMDS development by adding little steeper arch to their ICBM's or adding more countermeasures.