With a renewed focus on nuclear stockpiling among certain state actors, there is an urgent need to identify successful pathways for nuclear disarmament. History has demonstrated that this is an achievable goal, with important lessons for contemporary security discourse and policy. The potential lessons extend beyond purely security dividends, with potential contributions to economic and environmental discourses as well. The case presented in this contribution - titled at different times the HEU Deal, the Grand Uranium Bargain, or Megatons to Megawatts M2M - was the product of sustained cooperation between enemies (USA - USSR/Russia) and multiple stakeholders. It was an early, still little-known, yet useful component of just transitions to climate-compatible societies. The positive results of this actual cooperative disarmament case significantly contribute to the moral argument for nuclear disarmament with a practical, almost utilitarian rationale. The larger framework of transitions to climate-compatible societies creates a broader motivational framework that must be employed to properly evaluate the results of actual nuclear disarmament cases and the need for sustained cooperation. »» TDHJ «« » patreon: https://www.patreon.com/thedefencehorizon » donate: https://tdhj.org/about/#donation »» HOME «« » https://tdhj.org/ »» SOCIAL MEDIA «« » X (formerly Twitter): https://x.com/HorizonDefence » Facebook: https://www.facebook.com/thedefencehorizon.org » Instagram: https://www.instagram.com/thedefencehorizonjournal/ » LinkedIn: The Defence Horizon Journal