Chapter 2: NATO Enlargement – Lessons from Central and Eastern Europe

This paper examines why Central and Eastern European (CEE) states adopted NATO membership as a core strategic objective after the Cold War and identifies lessons relevant to contemporary aspirants such as Ukraine. Through historical analysis and policy-focused interpretation of regional developments from the early 1990s to the 2000s, the study traces how security vacuums, the legacy of Soviet domination, and fears of renewed Russian imperialism shaped the foreign and security policies of CEE governments. It highlights Poland’s early and coherent pursuit of NATO integration—supported by broad political consensus, diplomatic engagement with key Western partners, and extensive reform of civil–military structures—as a central case demonstrating how sustained lobbying and alignment with Alliance norms facilitated accession. Comparative discussion of the Baltic States underscores the additional challenges faced by newly independent countries with limited defence capacity but strong political commitment. The paper also analyses the constraints of NATO–Russia relations, internal Alliance scepticism, and the continuing interoperability and reform demands placed on new members. It concludes by outlining lessons for Ukraine, emphasising the importance of consistent strategic vision, coordinated diplomacy, resolution of bilateral disputes, and cultivation of supportive public opinion among NATO members.