S 2 E 11, Alan and Julia and the stupid choice

Alan Faragut and Julia were talking about "mother", the plant that would cause sterilization which Julia wanted to give to Ilaria. She wanted to do this to prevent Ilaria from releasing Narvik C and wiping out nearly the entire population of the earth..

Alan argued with her, saying it was immoral to cooperate with Ilaria.

I thought that was stupid to have Alan take that position. He knew the alternative. If he didn't temporarily sterilize men, Ilaria would kill nearly everyone.
He is a smart and rational person. I have a hard time thinking his hate for Ilaria would prevent him seeing the right choice, prevent him from choosing temporary sterilization over worldwide genocide.