At the Nuremberg trials, during a discussion of Just War Doctrine, a point was reached where they needed to distinguish between just reasons to go to war, and just specifications of how war should be fought. Jus Ad Bellum
is "when it is right to go to war". How war should be fought is Jus in Bello.
In a statement released by the Vatican entitled 'Gaudium et Spes
', the following point was made -
"... any act of war aimed indiscriminately at the destruction of entire cities or of extensive areas along with their populations is a crime against God and man himself."
There have been a number of attempts to rule out the use of certain weapon
s in warfare
, perhaps the first of which was the attempt to try and rule out the use of crossbow
s and siege weapon
s. These rules only applied in wars between Christian
s however, there were no such rules when waging war on non-Christians.
The Nuremberg Trials caused two criteria to be set for how war should be carried out.
The first was discrimination. This involves drawing a line between killing military personnel and killing civilians. This does not mean that war shouldn't be carried out because civilians might accidently die, it's a case of drawing a line between accidental and intentional killing of civilians. It is held that Just War must discriminate.
The second was the matter of proportionality. The methods used and suffering caused by the war must be proportional to the injustice which made the war take place.