Ed Morrissey has hit this nail on its head:
Russia has not covered itself in glory in recent months, even apart from the increasingly autocratic domestic policies of the Vladimir Putin administration. One of its former agents wound up dead through poisoning by polonium after he started criticizing Putin. Now a sample of HEU winds up on the black market, and Russia won't cooperate.Why we keep acting like they're our friends is beyond me. I sometimes think this facade of "good relations" is just to keep Russia quiet and out of our way.
We used to excuse the exceptions to good relations from Russia and Putin. It's difficult to see anything else these days.