A full-scale Russian invasion of Ukraine seems imminent, but nobody really wins if this happens. The global economic and food security impacts would fall disproportionately on the most vulnerable. Catholic concern for the common good and just war principles require us to look for a diplomatic solution that might avert the evils such a conflict would unleash. In particular, a personal intervention by Pope Francis may be our last hope for successful negotiations to preserve peace. Notably, Pope Francis writes in "Fratelli Tutti" that "it is very difficult nowadays to invoke the rational criteria elaborated in earlier centuries to speak of the possibility of a 'Just War'" (No. 258), in part because of the destructive power of modern weapons. However, this does not mean contemporary Catholic ethics calls for unqualified pacifism; the just war framework allows leaders to judge whether military action is reasonable in light of traditional principles and pragmatic considerations.