In the United States, we have a system of representative government wherein the people have responsibility for the common good. One of the essential elements of Just War Doctrine is that a Just War MUST be waged by the “proper authority.” That’s YOU and I via our elected representatives in Congress. So the Cathechism says that, “The evaluation of these conditions for moral legitimacy belongs to the prudential judgment of those who have responsibility for the common good.” That means that the proper authority (Congress) must evaluate whether or not a potential war will meet the conditions of Just War Doctrine. They may apply Just War Doctrine correctly or incorrectly, and such a decision will be visible for all of us to see whether or not it followed the criteria mandated by the Cathechism. It’s really not that hard.
Now as to your allegation that I misinterpreted the quote of the Holy Father, I will again provide the relevant quote and my interpretation of it. It is your task not just to say that I’m wrong but to DEMONSTRATE that my argument is flawed. Here it is again:
“3. Not all moral issues have the same moral weight as abortion and euthanasia. For example, if a Catholic were to be at odds with the Holy Father on the application of capital punishment or on the decision to wage war, he would not for that reason be considered unworthy to present himself to receive Holy Communion. While the Church exhorts civil authorities to seek peace, not war, and to exercise discretion and mercy in imposing punishment on criminals, it may still be permissible to take up arms to repel an aggressor or to have recourse to capital punishment. There may be a legitimate diversity of opinion even among Catholics about waging war and applying the death penalty, but not however with regard to abortion and euthanasia.”
Ratzinger says that there may be a “diversity of opinion about waging war.” There are only two types of wars, as far as Catholics are concerned: Just Wars and Unjust Wars. There can never be a “diversity of opinion” about the waging of Unjust Wars. There can also be no “diversity of opinion” regarding the criteria that must be met for the waging of Just Wars - those critieria are clearly spelled out in the Catechism. But ONCE a war meets those criteria, THEN there may be a diversity of opinion about whether that war** MUST **be waged.