What do you do with a prohibitively expensive weapons system that cannot perform its designated function, that is intended to deal with a nonexistent threat, that is rejected by most of the supposed beneficiaries, and is opposed by the Joint Chiefs and most senior members of the Department of Defense? If you are the Obama Administration and the weapon system in question is the proposed missile defense shield intended to be based in Poland and the Czech Republic, you cancel it.
This missile defense system was sold by the GW Bush Administration as protection for Western Europe from a future threat from Iranian long-range missiles. But the real goal may well have been to assuage Polish (and Czech) fears of Russian irredentism. Since Iran lacks both nuclear weapons (at least, as of now) and long-range missiles, the real target of this system may well have been US-Russian rapprochement. The shift to a seaborne system based in the eastern Mediterranean and using existing technologies should help ease tensions with Russia and could actually threaten Iranian missiles (and protect Israel). Plus, the canceled plans' unpopularity in much of Europe will remove a source of irritation between the US and its closest allies.
Since Ronald Reagan first proposed Star Wars missile defense in 1983, all these efforts have done is eat vast quantities of money (some estimates claim over $250 billion to date) with little to show for it other than some great names. My favorite is "brilliant pebbles," a space-based system of autonomous mini-satellites that would intercept passing ICBMs and protect us all. Unfortunately, the technology did not prove to be feasible.
Of course, none of this stops John Bolton and his neocon friends (Joe Lieberman, for one) from screaming bloody murder about the policy shift. Their concern is Russia, and they view the cancellation of the radar in the Czech Republic and the 10 missile launchers in Poland as a devastating setback for containment. The fact that deployment was still a decade away and that the new plan includes the possibility of deploying a revised set of launchers in Poland only a few years later than the Bush plan is carefully ignored. Facts are not important when there are political points to be made.