ABSTRACT
This chapter examines NATO's multifaceted role in the context of Russia's 2022 invasion of Ukraine, addressing three key questions: the extent to which NATO's actions deterred or contributed to the conflict, how the war transformed NATO's membership, force posture, and priorities, and NATO's impact on the war's trajectory. Prior to 2022, NATO's ambiguous enlargement policy – promising Ukraine eventual membership without concrete security guarantees – coupled with limited defense spending and continued economic ties with Russia, created a permissive environment for Moscow's aggression. While NATO did not provoke the war, its restrained support for Ukraine and modest military posture after 2014 undermined deterrence. Since the invasion, NATO has undergone a significant transformation. Finland and Sweden's accession strengthened the Alliance's northeastern flank, while enhanced cooperation with the EU and non-European partners like Japan and South Korea bolstered collective defense. NATO's command and force structures were overhauled, with the Enhanced Vigilance Activity expanding to new eastern members and a new force model enabling rapid mobilization of up to 500,000 troops. The Alliance refocused on deterrence and defense, reconfiguring crisis management and cooperative security to counter Russia's destabilizing actions. Operationally, NATO's intelligence sharing, training, and arms transfers were critical to Ukraine's survival, though delays in delivering advanced weaponry limited Kyiv's ability to decisively counter Russia. The chapter concludes that NATO's pre-war hesitancy contributed to vulnerabilities, but its wartime adaptations and support have been pivotal in sustaining Ukraine. However, ongoing caution in sanctions and military aid has prolonged the conflict, highlighting the need for a more proactive strategy to ensure European security and counter revisionist powers effectively.
