The way Danny was storming from her flat told her who was in there, and how pleasant he was generally being.
The Doctor was there, in her favourite chair, idly flicking through channels.
"You couldn't get along with him for one minute. At all."
"PE's no good for you."
"And you expressed that opinion."
"Soldiers only learn through repetition. And I thought he'd get the message by now."
"And you staying away from the whole soldiering thing yourself."
The Doctor slowly swiveled his head towards her. Eyebrows optimising to attack position.
"At least when I met you when you had the big leather jacket, you were a lot more pleasant. Given the way you're behaving, maybe I'm better off with soldiers."
The Doctor was out of her chair and in her face faster than she could register.
"I know. I know how soldiers think, Clara. I know. I lived with it longer than people, than countries, than ideas live."
"Then you should at least pretend to empathise-"
"They think of duty. Of honour. Of all sorts of justifying excuses of Why It Has To Be Done. They know what has to be done, and they march to the top of the hill and plant their flag and they do it."
The Doctor was only warming up to his rant level. "Afterwards they feel the guilt or maybe none at all, but they made their decision before the order was given, and regardless of what happens after, they Do Their Duty."
"And you know what? When a war starts, everyone eventually starts thinking like soldiers. Even those who try to move around the edges, trying to find a way around the death and destruction starts to think like a soldier."
Now he was millimetres from her face, spittle flying. "And after, when there's one soldier standing? The winner of a battlefield bigger than your tiny little mind can comprehend? Long afterwards, when he realises that there was a way he could have ended it? He realises that if he stopped thinking like a Soldier … and started thinking like a Doctor at the very beginning like he was supposed to, he might have saved everyone at the start."
He stopped, and slumped back into her chair. "Don't you see, Clara? A soldier doesn't think. A soldier has already decided. All you can do, is hope that the soldier's decision has your best intentions at heart."
Clara had already left. Maybe they could stop at that new Thai place down the road.