I have a new theory about George Bush. Having fucked up the world badly in his own presidency, he's now trying to stir up as much trouble as possible to leave to his successor, maybe in the hope that he'll look less bad in comparison.
So, Bush may want to stop Iran acquiring nuclear weapons, but thinks it's worth tweaking the tail of the Russians by stationing missiles next door and turning down their offer of collaboration on a genuine anti-Iranian military project. Predictable result : more Russian / Iranian co-operation, higher-probability of Russian nuclear expertise getting to Iran, lower probability of Russian diplomatic support for sanctions against Iran. Meanwhile, he's trying to hurry along the breakup of Serbia (unpopular with both Serbs and Russians) that may re-ignite war in Kosovo.
There's also recent talk that the US military in Iraq will retreat into Kurdistan with obvious issues for US / Turkish relations, starting, er, now.