what do you mean "fair game"? by the same logic russia attacking ukraine is also "fair game".
"hei cmon im just atacking my neighbor its fair game, what else should i do"
I mean what I said: if you're being attacked by drones, then no one can fault you for trying to sabotage the production of those drones, even if they're made in a different country than the one which is sending them against you.
But, you can and should fault Russia for getting into that position in the first place, that their neighbor is attacking them back with drones.
Let's say I pay someone to punch you int the face every day. Then one day when you punch me in the face do I have a right to complain?