This is the age old question.
How do you fight Evil without becoming Evil yourself?
As you point out, they have no rules. What has “take the high road” gotten normal, decent peaceable people so far? I keep hearing “Don’t take the bait! That’s what they want!”
And I agree, but don’t be surprised to hear someone at the back of the overstuffed railroad car yelling “don’t provoke them, it will just make them mad!” as the train clickety-clacks down to the gulag.
God fights evil and stays good. The act of fighting is not inherently evil.
Bravo! You nailed it!