TIL Robert Oppenheimer thought highly of physicist Hans Bethe and chose him to head the Theoretical Division at Los Alamos. After the War, Bethe declined to participate in developing thermonuclear weapons as he believed that the world would not be worth preserving after a war with such weapons

https://www.osti.gov/opennet/manhattan-project-history/People/Scientists/hans-bethe.html

https://www.reddit.com/r/todayilearned/comments/154atak/til_robert_oppenheimer_thought_highly_of/