"Successive U.S. administrations have urged the creation of an anti-missile system to protect against threats from rogue states. The Bush Administration believes that North Korea and Iran are strategic threats and questions whether they can be deterred by conventional means. The Administration has built long-range missile defense bases in Alaska and California to protect against North Korean missiles. The system has been tested, with mixed results, and questions have been raised about its effectiveness. The Administration has proposed deploying a ground-based mid-course defense (GMD) element of the larger Ballistic Missile Defense System (BMDS) in Europe to defend against the threat of long-range missiles from Iran. The system would include 10 interceptors in Poland, a fixed radar installation in the Czech Republic, and another forward deployed radar elsewhere in the region, but closer to Iran. Deployment of the European GMD capability is scheduled to be completed by 2013 at a cost of $4.04 billion. The proposed U.S. system has encountered resistance in some European countries and beyond. Critics in Poland and the Czech Republic assert that neither country currently faces a notable threat from Iran, but that if American GMD facilities were installed, both countries might be targeted by missiles from rogue states - and possibly from Russia."
CRS Report for Congress, RL34051