Ukraine and NATO

I don't have any kind of principled problem with the idea of NATO membership for Ukraine, but given that Russia seems very opposed to the idea it seems mighty odd for Bush to be pushing forward on the subject at this particular moment. It seems to me that it was just a few months ago when Iran's nuclear research programs were the greatest threat to humanity since Hitler and we were eager to secure Russian cooperation on UN action against Iran. But now we want to antagonize them over something that's not going to make any difference whatsoever to Americans one way or the other?

The failure of U.S. policymakers to set priorities is a bit baffling. Why not ease up on Ukraine and try to work with Russia on stuff that matters more? It's not as if getting Ukraine into NATO will be some kind of boon to American security.