He's reacting to Obama's comments "caught" on mic. I would've figured republicans would've been mad because Obama was presuming he'd win re-election. But noooo. Romney's trying to make a mountain out of a molehill. Frankly, I don't get the beef at all.
Neither does Obama, who teased about it later today.
It also should be noted that Obama's been working hard to establish a working relationship with Russia. He doesn't need some hack coming in and making up stuff. If we get a republican president we'll be back to "axis of evil" crap.