"I believe you can understand the dangers we're facing better than anyone. You were there in Ame, weren't you? No, don't be afraid. I know you were just following orders. But you saw for yourself the danger people like Hanzou and the Akatsuki can pose to Konoha. The attacker could have been any one of them. It's because of disasters like this that I try to get rid of threats like the Akatsuki pre-emptively. It's too late by the time their plans come to fruition. You understand don't you, Kakashi? It's all to protect us, to protect Konoha.
"Sacrifices have to be made for the greater good. It's the reason why Minato sealed the Kyuubi into his own son. It's the reason why so many have given their lives in war. And it's the reason why ROOT exists: to support the village like a tree's roots anchored within the earth. People glorify what is happening in the sunlight and all the idealism that comes with it, but we know that what's happening in the dark is just as important. It's down-to-earth, gritty realism that ensures Konoha's survival, not niceties. People end up condemning us because they don't want to face this side of reality. But Kakashi, you're smarter than that. You know what it's like to be on this side — the side that no-one sees. That's why you've stayed in ANBU.
"You don't need their approval," Danzou declares firmly. "You don't need to listen to all the condemnation that they heap on you. But ROOT needs you. You'll be able to do great things in ROOT, Kakashi, if only you break free of all that unreliable sentimentalism and go back to what it really means to be a shinobi."
There's a fear creeping up on Sakumo that the rattled uncertainty reflected in the hunch of Kakashi's shoulders is becoming more genuine than not. For someone who has hardly spoken ten words to Kakashi his whole life, Danzou knows him unnervingly well. Just how long has Danzou been watching him? Like a Hyuuga in a fight, Danzou is shutting down every tenketsu he can jab.
Despite all the anger and disapproval towards Danzou that Kakashi has carefully bottled up inside of himself during those months in Ame, what the elder has just torn open are years-old wounds. The million half-healed, half-scarred lacerations in his heart that every careless accusation has carved into him.
It begins with being the son of his disgrace of a father, then the Sharingan that he stole from a dead teammate, then the friend that he murdered in cold blood, and now, the sensei he wasn't able to save and the jinchuuriki outsider he was much too close with. And how many more will there still be? These are the things which cut deepest into the soul, not the abstract wrongs that Danzou has committed in a faraway land. These things cut away and cut out; isolating Kakashi with every barb that buries itself in his flesh.
And here, Danzou is saying "I understand". He is saying "we're the same".
By appealing to Kakashi's sense of duty towards his village and fanning his resentment towards the same, Danzou is isolating Kakashi. By forgiving him for killing the ROOT agents in Ame, Danzou is putting Kakashi in his debt. And by using everyone from Minato to Hanzou in a thorough mix of rhetoric and logic, he is constructing a facade of honesty over his lies.
Geniuses are susceptible because they can't help but think too much. Acting is even more perilous because falsehoods and truths feed each other much too easily. Kakashi's hand goes to his Sharingan, a gesture borne of unconscious habit. His fingers brush his hita-ate, hesitating.
"Obito," Rin whispers, because she's becoming worried too, caught as she is in the twisted half-truths that Danzou and Kakashi are both spinning with their words and reactions. "Don't forget Obito."
Kakashi's hand lowers and drops back to his side. "What do you want me to do, Danzou-sama?" he asks at length.
The kindly smile that Danzou gives Kakashi makes Sakumo shudder. "Consider my offer. Think about what it really means to protect this village."
'Yes, yes, buy some time to think this through—' the elder Hatake cajoles silently in his mind.
"No," Kakashi replies softly, his voice steady with conviction as he squares his shoulders. "I've decided. Danzou-sama, what do you want me to do?"
Sakumo's stomach plummets and Rin crouches down, hiding her face against her knees. It doesn't matter if Kakashi is acting anymore, not when he has just promised Danzou himself. The satisfied gleam in Danzou's eye makes an awful, frozen anger solidify inside Sakumo.
"If you're going to join ROOT, you'll need to make sure that no-one will be able to report you to Hiruzen. Your taichou, Snake, she was once in ROOT, did you know...? Ah, so you do. I don't know what she has told you, but she has been trying to tear apart my organisation for years. She won't understand why you would want to join ROOT — she's like Hiruzen, much too idealistic. She won't hesitate to turn on you if she thinks it necessary, so we have to act first."
The blankness of Kakashi's expression is the type that precedes a particularly bloody use of Chidori. "Would it not be enough to distance myself from her...?"
A grimace presses Danzou's lips into a thin line. "She knows ROOT too well, unfortunately. We can't have Hiruzen restricting us again, not when we are facing an unknown threat powerful enough to wield the Kyuubi. If we don't become stronger quickly, when we are attacked again, Naruto will be at risk. It's better to get rid of potential obstacles once and for all."
They both know it's a test of loyalty; an initiation. Danzou is greedy enough to want Kakashi's soul and everything else besides it. Still, when Kakashi hesitates, Danzou allows it. 'It wouldn't do to push too hard and scare him away, after all,' Sakumo thinks bitterly.
"Those who break the rules are scum, but those who abandon their friends are worse than scum," Kakashi whispers, his gaze downcast, and Rin looks up with a hopeful shine in her eyes. "I won't let another one of my comrades die by my hand again."
Danzou exhales on a drawn out sigh. "I understand your sentiment for your teammates and your friends, but things aren't so simple here." The elder regards Kakashi pityingly. "How much do you even know about your taichou?"
The teen startles. "How much do I...?"
"She hasn't told you anything, right? Do you even know her real name?" At Kakashi's frozen countenance, Danzou only plunges the knife deeper. "How can you trust someone who doesn't trust you?" Kakashi tears his gaze away, tense with sudden hurt, and Danzou continues on relentlessly. "Do you know why she joined ROOT in the first place? She wasn't like you — she didn't join for the good of the village. She had murdered her father, and she wanted to cover it up." A self-deprecating sound escapes the elder's throat. "I gave her a second chance because I saw the potential in her, but in the end, she betrayed us all."
Kakashi has nothing to retort with because Snake had really told him nothing about herself and her past. He rubs restlessly at his covered eye again, a deep frown creasing his forehead.
"She's not like your teammates, or your sensei. She's a danger, Kakashi, not a friend."
A/N: These two chapters really gave me a dilemma. On one hand, I want Danzou to appear reasonable because reasonable villains are the most interesting (and dangerous) kind of villains. On the other hand, there's no way I want to justify Danzou's extremism, nope.
So I'll just say this: the most important thing to Danzou is Konoha's physical survival, and only that (ROOT = screw mental health + happiness). But there are of course things which are more important, like morality.