• The legitimate purpose of any moral use of force is neither to kill as many as possible, nor to avoid all killing – it is to remove a threat, to stop an aggressor.
When and where you open fire, and for how long, depends on the decisions and location of the enemy. If you are firing in self-defence, you are duty-bound to remove the actual threat, no matter how many or how few are killed.
If three armed gardai confront four armed robbers, but only one garda is killed by those robbers, the moral duty of the two surviving gardai is not to kill only one robber (because only one garda was killed) but to remove the actual threat facing them – which, in such a case, means firing on all four.
Moral judgment cannot be replaced by a simple count of the bodies on each side. Those in Irish uniforms killed more of those British khaki or police uniforms in 1916 than the reverse – does that set of numbers decide who was right? Is that how we judge D-Day? Or Gaza?
When George Mitchell brought peace to this island, entry to the talks process was based on parity of esteem, and rejection of both the threat and the use of force.