Introduction: Membership anniversaries and theoretical security models

The chapter provides theoretical frameworks for, and a general overview of, the book. First, alliance theory framework is examined, providing a theoretical perspective on how institutional factors can either diminish or increase distances between member states of an alliance. Second, a cluster of theories encompassed by “divergence and convergence” framework is highlighted. Based on realist, liberal, and constructivist theories, these theories examine non-institutional factors that explain variables leading to divergence and divergence of Eastern European states’ defense policies. Finally, we look at domestic and transnational factors that explain defense policy formation of states under consideration. The chapter ends with an overview of the countries encompassed in the book based on geography and factors of security and insecurity that the respective states feel.