Book excerpt: Sustainable Peace in Northeast Asia examines the causes of lasting and complex tensions in the region from underlying political, historical, military and economic perspectives; discusses their historical development and political-economic implications for the world; and explores possible solutions to build lasting peace. The book is unique in that it approaches the topic from the historical perspective of each constituent country in the region. Major global powers such as the United States and Russia have also closely engaged in the political and economic affairs of this region through a network of alliances, diplomacy, trade and investment. The book also discusses the influence of these external powers over the crisis, their political and economic objectives in the region, their strategies and the dynamics that their engagement has created. Both South Korea and North Korea have sought reunification of the Korean peninsula, which will have a substantial impact on the region. The book examines its justification, feasibility and effects for the region. The book discusses the role of Mongolia in the context of the power dynamics in Northeast Asia. A relatively small country, in terms of its population, Mongolia has rarely been examined in this context; Sustainable Peace in Northeast Asia makes a fresh assessment of its potential role.