The common thread was the inviolability of innocent life. That would incude all the medical/ethical issues (abortion, infanticide, euthanasia, suicide, destructive embryonic stem cell research, cloning, and IVF) plus an opposition to WMD's that are intrinsically indiscriminate, the so-called ABC weapons (Atomic, Biological, Chemical).
From the Catechism: 2314 "Every act of war directed to the indiscriminate destruction of whole cities or vast areas with their inhabitants is a crime against God and man, which merits firm and unequivocal condemnation. A danger of modern warfare is that it provides the opportunity to those who possess modern scientific weapons especially atomic, biological, or chemical weapons - to commit such crimes.
Some --- I daresy most--- Catholics are not aware that WMD's are just as "unequivocally" forbidden by Moral Law as abortion is, and for the same reason: they violate the right to life of innocent human beings.
There is also a tendency to ignore the anarchy that as much as ever distinguishes the international “order.” and, indeed, the “order” of every society. The soldier and the policeman are necessary actors in the scheme of things. It will be a long while, if ever, before the soldier can be reduced to the role of policeman or the policeman to the nightwatchman.
Yes. Exactly so.