Scholars and religious leaders disputed the view that Leo is trespassing when it comes to matters of armed conflict. In the Gospel of Matthew, Jesus delivered a series of blessings that included: “Blessed are the peacemakers, for they will be called the sons of God.”

The church has long grappled with such issues, and Leo isn’t the first pope to speak out: Pope John Paul II opposed then-President George W. Bush’s invasion of Iraq in 2003.

“Questions of war and peace have been the church’s lane for centuries,” John Carr, founder of the Initiative on Catholic Social Thought and Public Life at Georgetown University, said in an interview. “They’ve been thinking about the use of violence since the invention of gunpowder.”

Bishop Mariann Budde, of the Episcopal Diocese of Washington, D.C., told NBC News: “Speaking about war, peace and human dignity is squarely within the vocation of all religious leaders, because those are moral questions at the heart of the common good. When a political leader answers that witness with insults, he is treating moral accountability like partisan combat, and that says far more about our politics than it does about the pope.”

In his inauguration speech in January 2025, Trump said that he would measure success not only by wars won, but “wars we never get into.” Part of his political appeal has been his pledge to avoid overseas entanglements. In interviews, though, the people who came to hear him speak accepted his contention that the Iran war is necessary to keep the regime from acquiring nuclear weapons.

“There were a lot of wars in the Bible and they were justified,” said Penny Visser, 65, of Sun City, Arizona, who came to the Phoenix event with her daughter, Tori, 20, a college student. “What gives the pope the right to say no on this one.”