Catholic ethicists, whether defenders of just-war doctrine or pacifists, agree that the Russian invasion of Ukraine is not morally justified, according to the report. “Where Catholic moralists begin to disagree is on what means are appropriate in responding to the invasion.”

Some just-war theorists question whether armed resistance meets the criterion of “serious prospects of success” (Catechism of the Catholic Church, n. 2309). However, Gerald Beyer of Villanova University called for “more military aid from NATO and the EU (which they already are moving forward) to help the courageous and determined Ukrainians.”