Maybe that kid in the back is thinking, "Damn, that's some cool gear that guy's got on - wonder if he'll let me wear his helmet," or, "shit, I hope I don't get beat up by those asshole kids back in the neighborhood for this."
You can make whatever you want out of these pictures, if you want to be defeatist and negative all the time, go right ahead, but a kid's smile is hard to fake, and some day when they're older they might remember the kindnesses and sacrifices made for them by these soldiers and not pick up that gun or bomb to use against someone else.