Medium-term prospects for nuclear arms control collapsed with the demise of the INF treaty. Geographically, the nuclear theater has shifted east, making Russia more aggressive in defending state security. Doctrinally, ambiguity over use of low-yield nuclear weapons in densely populated Europe gives Russia political leverage, which it will not trade away easily. Technologically, the development and deployment of new non-strategic and cyber weapons complicate limitation and verification regimes. Geopolitically, the United States, Russia, and China show little interest in serious arms limitation as they hedge against security risks. And in public discourse, nuclear weapons are politically less salient today than during the Cold War. As a consequence, chances are slim that new nuclear arms agreements will be reached anytime soon to mitigate risks of miscalculation or inadvertent escalation. The threat environment is more dangerous today due to the conundrum of arms control in an era of great power competition.