The idea of a grand bargain between the United States and Russia is less popular in Washington than ever before. And yet one of the biggest foreign policy problems for the U.S. — that of North Korea — cannot be resolved without Russia's participation. In recent years, Russian President Vladimir Putin has made sure to rebuild a close relationship with North Korean dictator Kim Jong Un, and it's no longer enough to talk to China to mitigate the Stalinist state's aggressiveness.

Last Sunday, North Korea tested a ballistic missile that might be capable of reaching the U.S. military base on Guam. It fell in the Sea of Japan — according to U.S. reports, just 96 km south of the Russian port of Vladivostok. The White House said in a statement, "With the missile impacting so close to Russian soil — in fact, closer to Russia than to Japan — the president cannot imagine that Russia is pleased."

Putin's response was quick and unfriendly. While restating that Russia was against the proliferation of nuclear weapons, including to North Korea, he said Monday: