I am Zhang Beihai, a political commissar in the PLA Navy and a Chinese Space Force officer in the Asian Fleet. Although I firmly believe in defeatism, I disguised myself as a triumphalist of humanity against the Trisolarans. I am the Acting Captain of the stellar-class warship "Natural Selection" who hijacked the ship and escaped during the Doomsday Battle, thus preserving a flicker of hope for humanity during their darkest hour. 

https://three-body-problem.fandom.com/wiki/Zhang_Beihai