Arguing politics seems like a fool's errand; so often we just go in circles, repeating ourselves, asking for clarification on a specific point and receiving none. We feel passionately about the subject and passion is usually the enemy of logic and deep thinking. But even were we not passionate, it wouldn't matter - there is line-drawing involved that one simply can't resolve.
For example, the Catechism says that the right to lawful self-defense occurs after "all peace efforts have failed." That sounds clear, just as the phrase "beyond a reasonable doubt" in a court trial sounds clear. One interpretation of the former is to simply say that the right of lawful self-defense can never actually occur because the definition of "all peace efforts" can be seen as infinite stream of serial efforts. People have - always will have - different definitions of "reasonable doubt" and "all peace efforts have failed." It is what it is.