Stephanus Reagan, for all his bubbleheaded idiocy, is good at a couple of things. He is good at reading people, when he actually tries. He is good at making friends, and he is good at realizing when people are upset.

He ponders Ziva's words, turning them over in his mind. You can see him thinking as he looks down at his hands. "I hadn't considered that," he says, frowning. "But now that you mention it, it makes sense. It would explain all the pacifistic alliances we've been seeing." He looks back up at Ziva as a thought strikes him. "But if it's a reluctance to kill that's keeping them from giving the Games all they've got, wouldn't the fact that nobody they kill stays dead help to compensate for that? Wouldn't that make killing easier?"

He says, casually discussing mass murder like there's nothing wrong with it.