You could posit that the chief is speaking out of his ass, but the more probable theory is that higher up on the hierarchy some officers are sincerely convinced that they are leading the charge of the Most Moral Army in the World™, and meanwhile some hefty portion of the boots on the ground have decided to, like you’ve phrased it, kill everything that moves and fuck the rules of engagement.

No way. This is the Hannibal directive at play, at least indirectly.