Today, Obama leaves Asia having made no headway on the issue of North Korean denuclearization. In Japan, China, and South Korea, the president reaffirmed each country's commitment to bring North Korea back to the Six-Party Talks. But it's not clear how much good that would do: Pyongyang remains as unpredictable as ever. For the past decade, North Korea has participated in eight rounds of these negotiations -- a process aimed toward ending DPRK's nuclear program that also involves the United States, Russia, China, Japan, and South Korea -- and it's been rewarded with gradual loosening of economic sanctions. The outcome? A trail of broken pledges and two nuclear tests, the most recent one in May.