<i>the general principal that people will not be held criminally accountable for use of force reasonably scaled to deal with an imminent threat</i><p>As long as once the threshold of lethal force is reached, all lethal force in reply until the threat is over is legitimate.<p>Midway through it&#x27;s now almost total ban on guns the U.K. made self-defense with more force than being used on you illegal, first in the courts in the &#x27;50s and then by law in the &#x27;60s.  Outlawing effective self-defense then makes it that much easier to outlaw guns altogether.