The U.S. bishops' chair for doctrine issued a clarification on April 15 reaffirming that Catholic just war theory sets strict moral limits on the use of military force, emphasizing that it is not a political endorsement of war but a moral framework.
The statement came as President Donald Trump and Vice President JD Vance, the latter a Catholic, have taken issue with papal remarks claiming that "anyone who is a disciple of Christ" is "never on the side of those who once wielded the sword and today drop bombs."
Speaking at an April 14 event hosted by the conservative group Turning Point USA, Vance publicly criticized Pope Leo on his anti-war remarks, asking: "How can you say God is never on the side of those who wield the sword?"
Brooklyn Auxiliary Bishop James Massa's statement on the subject underscored that Christians are obliged to critically evaluate claims made in favor of armed conflict rather than assume moral legitimacy.
"For over a thousand years, the Catholic Church has taught just war theory and it is that long tradition the Holy Father carefully references in his comments on war," Massa said.
"A constant tenet of that thousand-year tradition is a nation can only legitimately take up the sword 'in self-defense, once all peace efforts have failed' (Catechism of the Catholic Church, no. 2308)," Massa noted.
Massa continued: "That is, to be a just war it must be a defense against another who actively wages war, which is what the Holy Father actually said: 'He does not listen to the prayers of those who wage war.'
"When Pope Leo XIV speaks as supreme pastor of the universal Church, he is not merely offering opinions on theology, he is preaching the Gospel and exercising his ministry as the vicar of Christ. The consistent teaching of the Church is insistent that all people of goodwill must pray and work toward lasting peace while avoiding the evils and injustices that accompany all wars," the bishop concluded.
Pope Leo XIV responded to Trump's public criticism by saying he has "no fear of the Trump administration" and will continue to proclaim the Gospel.
At the Turning Point USA event, Vance — who is publishing a book about his conversion to the Catholic faith — said if Pope Leo was "going to opine on matters of theology," his comments needed to be "anchored in the truth."
"In the same way that it's important for the vice president of the United States to be careful when I talk about matters of public policy, I think it's very, very important for the pope to be careful when he talks about matters of theology," Vance said.
Bishop Daniel Flores of Brownsville, Texas, who was elected vice president of the U.S. Conference of Catholic Bishops in November 2025, said in a statement on X on April 15 that "public officials may opine about theology, as is their right."
But "the successor of Peter teaches. This is his office," Flores said. "If what he teaches doesn't sound like what we want to hear, we should admit the likelihood that the problem is in what we want to hear and not in what he teaches."
Vance: 'Stick to matters of morality'
On Monday, Vance defended Trump's decision to post on social media, and later delete, an AI-generated image that critics said depicted the president as Jesus Christ. Vance described it as a joke that people misunderstood.
"It would be best for the Vatican to stick to matters of morality, to stick to matters of what's going on in the Catholic Church and let the president of the United States stick to dictating American public policy," Vance said in an interview on Fox News.
