From Talleyrand’s Memoires (v.3, pg. 422), a portion of a letter he sent home from London explaining the difficulty of his negotiating position during his mission in the early 1830s.
Un négociateur n’a pas aisément le ton haut et ferme quand on peut lui demander à chaque instant: Votre gouvernement existe-t-il encore à l’heure qu’il est?
A negociator cannot easily keep an upper-handed and strong tone when someone might ask at every moment: “Your government? Does it still exist right now?”