Polish Prime Minister Donald Tusk announced the agreement on national television shortly before it was signed by Deputy Foreign Minister Andrzej Kremer and US chief negotiator John Rood.
Mr Tusk said Washington had agreed to meet Warsaw’s main demands in exchange for hosting the 10 interceptor missiles in a former military base near Poland’s Baltic Sea coast.
In return, the US has agreed to help modernise the Polish armed forces and locate Patriot missiles and a garrison of US servicemen in Poland to beef up its air defences, Mr Tusk said.
Poland is reported to have demanded the extra security help as part of the deal after Moscow threatened to target its missiles at any eventual bases.
The US signed an agreement with the Czech Republic in July to base tracking radars there as part of the missile defence system.
The US wants the sites to be in operation by about 2012.
Flap is being facetious, of course.
What are the repercussions?
Russia will remain pissed off at the United States and Poland and target the ten interceptors with nuclear weapons. Big deal. This might worry other European countries but not the Poles.
And, Russia may try to base bombers in Cuba.
The latter would lead to a direct military confrontation with the United States.