Rev dear Rev: What is the purpose of just war doctrine if Christian western pre-emptive nations are not going to abide by it?

2309 is not 2112, it is not a date in the future calendar, which signifies the emergence of a musician boy from the caves of music persecution as described in the Californian rock album 2112 by Rush, but rather refers to the paragraph and article numbers in the Global Catechism of the Church dedicated to a modern restatement of medieval just war doctrine. 2309 lays down 4 conditions to a war that would make it a just war even if it is already a legitimate legally binding war. These conditions are -

1. Defensive - the war must be in defence mode, the aggressor invader must have inflicted grave, long-lasting, and certain damage;

2. Diplomacy - all other means to avoid war must have been exhausted;

3. Exits - there must be some serious attempt and possibility of ending the war;

4. Proportionate - the war conducted must be proportionate, it must not inflict too much destruction on the other side;

Addendum re Civilians from Evangelium Vitae and Veritatis Splendor - it must not lead to the needless killing of endless amounts of civilians. The evaluation and guestimation of these conditions pertains to those who have the care of the common good. So these are the conditions to be met in order to pronounce a war to be just. Bellum iustum. Christian nations need to ponder this doctrine in the Global Catechism. Needless to say the Addendum would rule out pre-emptive nuclear strikes on civilian centers of population, killing housewives and children. Western nations are to avoid such recourses to WMDs. Anyway, such medieval doctrines are not irrelevant in today’s world of advanced weapons.