I naturally wouldn’t hesitate to shoot him if it was necessary for my cause, and I should expect him to do the same to me

I do think that family ties ought to make a difference. After all, violent differences of opinion didn’t prevent you & me from remaining good friends did they. My attitude to Esmond is as follows – and I rather expect his to me to be the same. I naturally wouldn’t hesitate to shoot him if it was necessary for my cause, and I should expect him to do the same to me. But in the meanwhile, as that isn’t necessary, I don’t see why we shouldn’t be quite good friends, do you. I wonder if he agrees.

Unity to Jessica, 11 April 1937, ed. C. Mosley, The Mitfords: Letters between Six Sisters (2007), 106