This article analyzes the evolution, content, and fate of the back-channel negotiations between senior Soviet and Japanese officials in 1989–1990, a time of radical changes in most aspects of Soviet foreign policy. Sources that have recently become available—especially the private papers of Aleksandr Yakovlev and Anatolii Chernyaev and several recently published collections of documents—not only confirm what has long been suspected about this critical channel of negotiation but shed valuable light on motives and complications in Moscow that precipitated the channel's ultimate failure. Because Japanese documents on the matter have not yet been declassified, the article cannot offer a full account of these talks, but the Soviet documents are sufficient to indicate why a bilateral rapprochement has been so elusive.