Poland became a member of NATO in 1999.
The Missile Defense System Agreement reached between Poland and the U.S. under the Bush Administration was scrapped in September 2009 and a new agreement was formed by the Obama Administration in October 2009 to establish a Missile Defense System in Poland as a part of the European Phased Adaptive Approach (EPAA).
On September 15, 2011, a joint statement was released by the U.S. and Poland, calling for the Ballistic Missile Defense (BMD) Agreement of 2008 and it’s Amending Protocol of 2010 on the deployment of land-based SM-3 systems to go into immediate effect.
The U.S. BMD system, which will be hosted at Redzikowo Base, is part of the third phase of the European Phased Adaptive Approach (EPAA) with a timeframe for 2018.
Like similar Missile Defense System agreements between the U.S and Turkey, Romania. The planned Missile Defense System in Poland has been opposed by Russia.