The Polish Government has formally signed a deal with the United States that will allow the Americans to locate part of a controversial missile defence shield on Polish soil.
The deal follows 18 months of negotiations and was signed today at a ceremony in Warsaw attended by US Secretary of State Condoleeza Rice.
The US claims the missile shield is designed to protect the world from "rogue elements" in the Middle East.
However, Russia believes the system is part of a US plan to neutralise Moscow's nuclear deterrent.
The Kremlin has warned that it will have to redirect its missiles at Poland in response to the US move.