This would seem to put conservatives in the position of bashing both a Republican defense secretary and the U.S. intelligence community:
Defense Secretary Robert Gates says the decision to abandon the Bush administration's plans for a land-based missile defense system in Eastern Europe came about because of a change in the U.S. perception of the threat posed by Iran.
Reinforcing statements President Barack Obama made about anti-missile strategy, Gates told reporters Thursday that U.S. intelligence decided short- and medium-range missiles now pose a greater near-term threat than intercontinental ballistic missiles.
He said intelligence experts concluded the short- and medium-range missiles were "developing more rapidly than previously projected" in Iran. Gates said the previous administration's plans will be changed, moving away from the installation of a missile defense shield in the Czech Republica and Poland in the near future. He said a second phase to begin in 2015 could result in missiles being placed on land in Eastern Europe.
Biden also says much the same here.
The move certainly looks like the Russians got something for nothing. But among the conservative fulminations thus far I haven't seen a substantive, evidence-based response to this point.