Since Russia invaded Ukraine in February 2022, the debate on Catholic teaching on peace has taken a turn. As Tobias Winright recently wrote in Commonweal: “This war tests…the recent narrowing of the Catholic ethic of war and peace to nonviolence.” Indeed, thinking about Ukraine’s response to Russian aggression in the context of Catholic moral tradition requires a re-reading of Pacem in Terris—the highest moment in the modern magisterium of the Catholic Church on peace and war.
The encyclical was dated April 11, 1963—Holy Thursday—but it had been signed on April 9, in an event that was televised around the world. Images of Pope John XXIII signing his last encyclical (he would die less than two months later) filled the news. The New York Times published the text in its entirety in its April 11 edition. Pravda, the official newspaper of the Communist Party of the Soviet Union, professed Pacem in Terris “an initiative in favor of peace.” Mainstream and other publications all across the globe devoted similar attention.
Pacem in Terris arrived six months after the Cuban missile crisis, and largely because of it. The most dangerous moment in the history of the Cold War compelled John XXIII to ask Italian theologian Fr. Pietro Pavan to draft an encyclical on peace. The document and the attention it received reflected the central role the Catholic Church played in articulating the moral language of the nuclear age—a language that developed previous doctrine in some important ways.
Sixty years later, the war in Ukraine—along with the marginal and somewhat controversial role of Pope Francis and the Vatican—affects our reading of Pacem in Terris. Neoconservatives are using the occasion to highlight the encyclical’s “deficiencies.” That’s an ahistorical and disingenuous assessment. Nevertheless, certain pressing developments do force us to reconsider it in a new context. For one thing, the abandonment of nuclear-weapon agreements could herald a new arms race and raises the risk of nuclear proliferation. As the Holy See delegation to the UN stated in April during the General Exchange of Views at the United Nations Disarmament Commission: “Tragically, the lessons of the Cuban Missile Crisis are being forgotten and numerous arms control treaties have been discarded, reflecting a paucity of trust internationally and accelerating a worrying trend toward rearmament.” Additionally, the plight of Ukraine—a country that gave up its nuclear weapons in 1994 and is now defending itself against a nuclear power—might inspire other non-nuclear countries to seek out or develop their own nuclear weapons in hopes of deterring invasion. Finland’s April decision to join NATO, meanwhile, deprives Europe of a country whose neutrality was critical in formulating the 1975 Helsinki Accords—hammered out at a peace conference it hosted, and to which the Holy See made significant contributions. And as the invasion leads other countries to reconsider their longstanding neutrality, the Holy See’s recent invocations of a “new Helsinki” seem more and more like a dream.