You also use this issue to examine another one of Tony's principles and beliefs, his stance on killing. First he mentions killing people is bad in his conversation with the girl in the night club and then later in narration he says he had to kill an Extremis enhancile, but hated it. So Tony Stark pilots one of the world's deadliest weapons, but prefers to use it non-lethally? It seemed like he was saying that he'll kill if he has to, but only if it's absolutely necessary and even then he won't like it?
Yeah, he's a man of ironies our Tony. Even for those only who saw the movies he's a man who made weapons and he no longer makes weapons. He still lives with that on his head though. He can make jokes about it, but the fact that he's no longer making weapons shows how he considers things. He's a man who's willing to kill. He'll do it if he believes it needs to be done, but he'd rather do anything else. His feeling is, "If I was smart enough maybe I could find another way."
He does pilot the most powerful weapon on Earth and tries to use it for non-lethal peacekeeping means. He uses it a lot like Pepper Potts' Rescue armor, which was implicitly made to be non-lethal. But it's not a Rescue suit... but it's not War Machine either. [Laughs] Iron Man is a weapon and it's the reason why he's kept this technology away from people.
So he's not Spider-Man, a guy who won't kill at all. He's more like Captain America in that he'll kill if he feels it's absolutely necessary, but he won't like it. He's a guy who sold weapons and someone like that must be okay with the concept on some level.
I don't believe the reason Tony Stark stopped making weapons was because he felt killing was bad. He makes that joke here but his ethical problems are slightly different. It wasn't about the act of killing. He's definitely a man who could pull the trigger if it would save somebody's life. That's how I see it. I think Cap would kill, but Tony is a much more problematic character than Cap. He used to make weapons. That's how he made some of his fortune and his family have a history in this.