"You can be a policeman or a soldier, but not both."

Anyone remember reading that line in the novel? Looking back at that statement, I don't think that's entirely true. Because there's something called a "military police", and I know several branches of the army that has those, such as the Navy, for example. The TV show NCIS and the Jack Reacher novels is proof, since Jack Reacher is a military police officer and the NCIS are basically cops for the Navy.