OPINION - Pope Leo XIV and Trump: Clash of the two most influential Americans

• Trump administration's use of Biblical scripture and symbols to justify controversial policies will trigger new fights with the Catholic Church in the months ahead, especially if the war escalates.
• The clash between US President Donald Trump and Pope Leo XIV, who are the two most inf

Robert Stephen Ford is a former US Ambassador to Algeria and Syria.

Presidents and popes have disputed wars in the past. Pope Paul VI criticized the American war in Vietnam, saying that America was losing its moral standing. Pope John Paul II called the American invasion of Iraq in 2003 unjust and illegal. However, the clash between US President Donald Trump and Pope Leo XIV, who are the two most influential Americans in the world, about the war against Iran is without precedent.

The rift that preceded the war

The relations between the Vatican and the Trump administration were difficult even before the Iran war. Before the appointment of Pope Leo, Pope Francis in 2025 criticized Donald Trump's restrictions against immigration and the treatment of refugees and immigrants in American detention centers. In January 2026, three top Catholic Church leaders in the United States issued a report stating that American foreign policy was immoral. They pointed to reduced assistance to world health programs that have harmed tens of millions of people worldwide.

The American surprise attack on Iran on February 28 sharpened the dispute between the Vatican and the White House. The Trump administration portrays the war as a kind of holy crusade blessed by God. In his April 7 social media message threatening to destroy Iranian civilization, Trump exclaimed, "Glory to God!" while also saying that God ensured the success of the mission to rescue an American pilot whose plane was shot down over Iran. On March 26, US Defense Secretary Pete Hegseth told a press conference that military strikes against Iran enjoyed protection from God, and at a religious service in the Pentagon on April 1, he quoted from the Old Testament, asking God to "break the enemy's teeth."

The Pope responded on April 6 that Jesus called for peace and reconciliation, and he rejected politicians using God to justify war. His rebuke generated sharp counterattacks from Trump and some Republican Party leaders. Vice President JD Vance and Speaker of the House of Representatives Mike Johnson said the pope appeared not to understand the Catholic Church theory of just war. Several American bishops close to Pope Leo responded that it was ridiculous to suggest that the pope did not understand the theology and the theory of just war since Leo himself is from the branch of the Catholic Church founded by Augustine, the Christian thinker who, 1,600 years ago, first set down the principles of a just war. The surprise American attack in the middle of negotiations, the American failure to avoid striking civilian targets and the ambiguous American government goals of the Iran war did not meet the standards of a just war, they noted.

Politics dressed as theology

Trump and the Republicans are politicians, not theologians. They portray the war against Iran as holy because they understand that the war is unpopular in the United States and they need the support of Christian conservatives in their political base. Notably, most Catholics, who are about 20% of the American population, voted for Trump in 2024. Opinion polls since late March have shown that most Americans doubt the war is in America's national interests. After Trump's threat to destroy Iranian civilian infrastructure and civilization on April 6-7, the pope called the threats "unacceptable" and would violate international law. He even urged American citizens to contact their representatives in Congress to demand that the war stop. It was unprecedented for a pope to urge Americans to mobilize this way, and it directly touched a big part of the Republican Party base. Trump responded five days later with his social media message alleging that the pope appears to accept that Iran can have nuclear weapons and does not understand foreign policy. No American president had attacked a pope so personally. With economic damage from the Iran war and opinion polls indicating Democratic Party victories in the November congressional elections, the White House and Republicans are especially sensitive to criticisms towards their war policy.

The pope enjoys a big advantage over Trump in opinion polls in the United States, and Trump over the past four days has retreated a little. He said on April 16 that while he respected the pope's right to say what he thinks, Trump insisted that he would continue to say and do what he thinks is right. The pope, meanwhile, said on April 18 that he did not want to debate the president. The pope's role in the end is not to descend to politics but rather to stay on a high level focused on how people should live according to the principles of Christianity. This round of arguments has been winding down, but the Trump administration's use of Biblical scripture and symbols to justify controversial policies will trigger new fights with the Catholic Church in the months ahead, especially if the war escalates.

*Opinions expressed in this article are the author's own and do not necessarily reflect the editorial policy of Anadolu.