The Intermediate-Range Nuclear Forces (INF) Treaty between the United States and the Soviet Union was a triumph of US and NATO nuclear deterrence and diplomatic strategies, bringing Moscow to the negotiating table and leading both superpowers to agree to completely and verifiably dismantle two classes (shorter-range [500-1,000 km] and intermediate range [1,000-5,500 km]) of nuclear-capable, ground-launched cruise and ballistic missiles. Three decades later, the treaty is in peril, with the United States announcing in February 2019 its intent to withdraw if the Russian Federation does not dismantle its treatyviolating SSC-8 missile. While Russia's decision to iolate the treaty catalyzed the present crisis, the context within which the treaty was negotiated has significantly changed since the late 1980s. The article discusses how these changes-the growth in shorter-range and intermediate-range (IRBM) missile arsenals in third states, the breakdown in the Cold War consensus on arms control, and the changing dynamics of US-NATO extended deterrence and assurance-led first Moscow and then Washington to reevaluate the merit of the INF Treaty. It concludes that the treaty's relative rigidity may play a key role in its undoing and suggests that future arms control negotiations develop more flexible and resilient mechanisms of review, dispute resolution, and verification.