NATO did not dissolve following the Soviet Union’s collapse and the end of the Cold War. Instead, the alliance expanded, in stages—from 16 members at its Cold War peak to 30 in 2020. While NATO enlargement alone did not cause the deterioration of US–Russian relations, it did contribute significantly to that outcome. Champions of NATO expansion aver that it maintains peace in Europe and promotes democracy in East-Central Europe. They add that Russia has nothing to fear. But Russia’s leaders have always seen NATO expansion differently. The article also examines NATO’s enlargement as it relates to US post-Cold War grand strategy. It contends the policy reflects the abiding US commitment to maintaining its global primacy, which, in part, is ensured by perpetuating Europe’s dependence on the USA for an elemental need: security. We conclude by considering the future of NATO and Europe.