Ground rod at each pole connected to a rod at the top of the pole. That's the simplest. The effectiveness could be questionable depending on if the pole grounded through the base has a lower resistance than the ground wire to ground rod.
I suppose you could use shield masts and/or shield wires like in a substation, but that is probably not practical, and possibly not viable.
Could look into changing to concrete or fiberglass poles.
"Just because you're paranoid, doesn't mean they're not out to get you"