Can you give suggestions for the intrigue play style

Can you give suggestions for the intrigue play style, I have difficulty because I have not played intrigue before, is there a tactic in intrigue to win a war, I start a conspiracy against someone I am in a war with, but since he is at war, my probability of success drops to 0, apart from that, what is the purpose of the tree on the far right in the intrigue tree, what does the torturer do?