Russia and North Korea have a historical relationship dating back to the beginning of the Pyongyang regime. The former Soviet Union had participated in the Korean War and its Air Force supported the communist forces on the ground. Moscow was the major donor in the reconstruction of postwar North Korea. The North Korean nuclear program had been initiated with Soviet equipment and training of nuclear scientists. Russia is a permanent member of the United Nations Security Council. All of these factors make Russia one of the countries with the most influence over North Korea. However, after Moscow had established diplomatic relations with the Republic of Korea in 1990, there were ups and downs in the relations between Russia and North Korea. First, the period from 1990 to 1995was the worst time for Russia-North Korea relations. Second, Russia’s influence was regained after the new treaty on Friendship, Good-Neighborly Relations and Cooperation with the North was signed. Moreover, the first trip for a Russian leader, Vladimir Putin, to North Korea was made in 2000. Third, since the beginning of the second North Korean nuclear crisis in 2002, Russia became an active participant in the Six-Party Talks. Russia realized that a balanced diplomacy toward the two Koreas works better for the interests of Russia rather than the pro-South Korean stance in the first few years of the early 1990s. In the 2000s, the overall relationship between Moscow and Pyongyang has improved. The railway connections of the TSR and TKR, and the construction of oil and gas pipelines through the Korean peninsula have been under discussion among Russia, North Korea, and South Korea. However, the process has been slow. The author has interviewed the former South Korean ambassadors to Russia in order to gain firsthand knowledge of Russia-North Korean relations. As to the overall Moscow-Pyongyang relations, the author shares the same views as the Russian experts about South Korea. However, they emphasized one particular point—North Korea’s debt to Russia. This was an issue that was rarely discussed in South Korea. In June 2012, Russia announced that 90 percent of the North Korean debt could possibly be written off. If the Russian initiative is approved, North Korea could join and initiate new projects with Russia. The Seoul government should be able to join the trilateral cooperation among Russia, North Korea, and South Korea. The Ambassadors’ advice needs to be taken seriously.