This book presents a comprehensive overview of political and economic developments as well as security issues in the Korean Peninsula during 2008–2020 from a Russian perspective. The authors offer a rich analysis of domestic affairs in both Korean states and the international situation they act in. The book’s first section, Diverging Development Paths, analyzes the evolution of North and South Korea in the early twenty-first century. The next section, The Nuclear Challenge, assesses Seoul’s and Pyongyang’s foreign policy options within ever-changing domestic and international circumstances – under the looming nuclear shadow. The final section, Partnering with Russia, presents an unprecedented first-hand account of Seoul’s and Pyongyang’s dealings with Moscow. The book provides a unique account with expertise from Russia, one of the four states directly involved in Korean affairs, providing insights on domestic and diplomatic decision-making of the two Korean states and international efforts to resolve the nuclear issue.