There are potential catastrophes so dire, only an approach that blurs the realist and the utopian seems appropriate. Take for example the Treaty on the Prohibition of Nuclear Weapons. Adopted by the United Nations in 2017, it seeks to completely get rid of the most satanic arms ever created.
The treaty’s already been signed by 84 states and ratified by 45. To take effect — that is, to be binding on its signatories — it needs only another handful of ratifications. And this week a group of 56 international bigwigs signed an open letter to nudge that along. They include former presidents and prime, foreign and defense ministers from 20 NATO member states plus Japan and South Korea, as well as one former secretary-general of the U.N. and two of NATO.
One of their stated objectives is to get the current leaders of their countries to sign the treaty. That’s cheeky, since all of the nations in question are presently under the U.S. "nuclear umbrella,” which they’d have to leave or disavow. Unlikely. Several, like Germany, even have American nukes stationed on their own territory.