Opposition to nuclear proliferation

Going through my father’s files I found this letter he wrote to his representatives in Congress opposing a proposed nuclear weapon project that was then referred to as the MX missile.

The MX missile system was deployed in 1985, renamed with some irony as the Peacekeeper. Of course none were ever used, and the last one was decommissioned in 2005.

I fully agree with my father’s assessment of nuclear weapons. At the same time I see nuclear proliferation as one of the few examples of humanity accomplishing some self-restraint on a global scale. Will we manage to repeat this feat with ecological threats like climate change, or technological threats like artificial intelligence?