Russia was particularly upset when, despite its efforts to cultivate the Stalinist regime of Kim Jong-il, North Korea test-fired missiles toward waters inside Russia's economic zone. And Moscow is certainly more concerned about North Korea than it is with Iran's nuclear program there's no payoff for Russia in Pyongyang's nuclear doings, and it has already caused plenty of trouble.
Whatever its outlook, the fact remains that there isn't much Russia can do about North Korea, for the simple reason that it lacks leverage over Pyongyang. On the diplomatic front, China is calling the shots; Russia's priority is simply to avoid being sidelined altogether from this key north Asian diplomatic initiative.
Fear of being rendered irrelevant explains Moscow's nervous reaction to the prospect of informal direct U.S.-North Korea talks on the sidelines, as mentioned by U.S. delegation chief Christopher Hill. The Russian Foreign Office leaked comments of its senior official to a Moscow daily to the effect that "We're not going to let the Americans monopolize any contacts outside the six-party talks format." That sounds as resolute as it is ineffective: Unlike the U.S., Russia has neither the stick nor the carrot that could change North Korea's behavior.
The limits on Russian influence were made clear in July 2000 when Kim Jong-il pulled a fast one on Russia's then-rookie President Vladimir Putin. Back then, Kim told Putin who visited Pyongyang en route to his debut G8 summit in Okinawa that North Korea would scrap its missile programs if other countries agreed to blast its satellites into orbit for the purposes of "peaceful space exploration." Putin tried to play Kim's statement as a trump card in his case against Washington's plans to develop a national missile defense system. But, the following month, the North Korean leader told his South Korean guests: "I made this and other remarks as a passing, laughing matter. Putin did not respond at the time, but later seized on it firmly and things happened like that."
To avoid being the butt of another such friendly joke, Russia has to be cagey about Pyongyang's constant requests for support in return for promises of good behavior that never get delivered.