At its simplest, a small drone is an eye in the sky, giving what every commander has wanted for centuries: a view of what is happening on the other side of the hill, or in the middle of the forest, or just down the next street, without having to send troops. Aerial reconnaissance was previously confined to higher levels of command and only gradually filtered down the chain; now every squad leader can have a folding Mavic Mini 2 small enough to fit into a cargo pocket but able to send back HD video from three miles away for half...