Educate yourself:

Phase One (2011 timeframe) will address short- and medium-range ballistic missile threats by deploying current and proven missile defense systems. It calls for the deployment of Aegis Ballistic Missile Defense (BMD)-capable ships equipped with proven SM-3 Block IA interceptors. In March of this year the USS Monterey was the first in a sustained rotation of ships to deploy to the Mediterranean Sea in support of EPAA. Phase One also calls for deploying a land-based early warning radar, which Turkey agreed to host as part of the NATO missile defense plan. Phase Two (2015 timeframe) will expand coverage against short- and medium-range threats with the fielding of a land-based SM-3 missile defense interceptor site in Romania and the deployment of a more capable SM-3 interceptor (the Block IB). On September 13, the United States and Romania signed the U.S.-Romanian Ballistic Missile Defense Agreement. Once ratified, it will allow the United States to build, maintain, and operate the land-based BMD site in Romania. The missile defense system in Deveselu became operational on 18 December 2015.[26] Phase Three (2018 timeframe) will improve coverage against medium- and intermediate-range missile threats with an additional land-based SM-3 site in Poland and the deployment of a more advanced SM-3 interceptor (the Block IIA). Poland agreed to host the interceptor site in October 2009, and today, with the Polish ratification process complete, this agreement has entered into force. Phase Four (2020 timeframe) will enhance the ability to counter medium- and intermediate-range missiles and potential future inter-continental ballistic missile (ICBM) threats to the United States from the Middle East, through the deployment of the SM-3 Block IIB interceptor. Each phase will include upgrades to the missile defense command and control system.