Vengeance and retaliation are the themes of countless books and movies. Clint Eastwood portrayed it in Fist Full of Dollars, Dirty Harry and Unforgiven. Liam Neeson followed suit in Taken and Cold Pursuit. In recent years, vengeance and revenge have become a major theme in politics. If someone wrongs you, never forget. Get even. In most of these stories, as in life, the path of vengeance does not …