North-eastern flank: Militarisation of the Baltic frontier

As part of a two-volume series, this report provides a critical analysis of the NATO’s north-eastern flank—Poland, Lithuania, Latvia, and Estonia—as a vital bulwark against evolving Russian threats. It examines how the four countries have transitioned from post-Soviet vulnerabilities into pivotal contributors to NATO’s collective defence through unprecedented military modernization, strategic infrastructure development, and societal resilience. Shaped by their history of external domination and a pressing need to counter regional threats, these countries have integrated NATO forces, and operationalized total defence strategies. All four states have well-exceeded NATO’s 2% GDP defence spending benchmark and are aiming for 5% and above in the coming years. Enhanced deterrence frameworks, including NATO’s Enhanced Forward Presence and joint regional capabilities, have fortified the region’s capacity to counter conventional and hybrid threats. Despite these advancements, critical gaps in civil defence infrastructure and resource mobilisation remain. This report analyses the region’s indispensable role in NATO’s deterrence-by-denial strategy and offers actionable recommendations to address vulnerabilities, ensuring sustained readiness and the Alliance’s long-term security posture.