And we know it is alive how?
Just from what I've seen over the years, puppies do go motionless when picked up by the scruff of the neck -- which is the way the mother would pick them up. I didn't see anything in the video that leads me to believe the puppy was already dead. This should at least be investigated (I would do so first simply because it is bad PR to have Marines throwing puppies off of cliffs -- it's not something that should be excused or justified). If not fake, the act is disgusting and these Marines should get more than just a slap on the wrist.