Following recent social media disagreements between President Donald Trump and Pope Leo XIV surrounding the Iran war, U.S. House Speaker Mike Johnson used the “just war theory” to defend the president’s criticism of the pontiff.
Johnson, a Louisiana Republican, insisted Wednesday he’s not one to criticize clerics or religious leaders, but he leaned into what he called the just war doctrine when it comes to the U.S. military action against Iran.
“I don’t want to engage in a theological debate with the pope,” Johnson said. “These are matters that people of good faith and good sense can debate.”
War of words
The pope used his Palm Sunday message to emphasize that God “does not listen to the prayers of those who wage war.” On Easter Sunday, Trump posted a profane message, threatening Iran’s power plants and bridges.
On April 7, Trump threatened to bomb Iran and eradicate a “whole civilization” — comments the pope called “truly unacceptable.” Trump retaliated Sunday. He called Leo “weak on crime,” told him to “focus on being a great pope, not a politician,” and posted an AI-generated photo depicting himself as Jesus.
Johnson said that he asked Trump to take down a social media post that was interpreted as the president depicting himself as Jesus.
What is just war doctrine?
According to the U.S. Conference of Catholic Bishops, the just war theory is a longstanding Catholic criteria used to determine whether or not war should be pursued. It states that “a nation can only legitimately take up the sword in self-defense once all peace efforts have failed,” according to a statement the organization’s chariman, Bishop James Massa, issued Wednesday.
War is only considered just when it is done as “a defense against another who actively engages war,” Massa said.
Charles Gillespie, an associate professor of Catholic studies at Sacred Heart University in Connecticut, told TribLive that war may be viewed as necessary “because of sinfulness and the fact that defending communities from evil is something that Christians are called to do.”
The pioneers of the just war doctrine were Saint Augustine and Saint Thomas Aquinas, according the national Archdiocese for Military Services.
Augustine stated that those who “waged wars on the authority of God” did not violate the sixth commandment, which forbids killing, the archdiocese said. Aquinas furthered Augustine’s theory, developing the conditions of a just war.
The Catholic Church today defines just war under the following criteria, according to the archdiocese:
• Damage inflicted by the aggressor on the nation must be lasting, grave and certain.
• It must be determined that all other methods of resolving the conflict are impractical or ineffective.
• There must be serious prospects of success.
• The use of weapons must not create “evils and disorders graver than the evil to be eliminated.”
Gillespie said the recent disagreements between Trump and Leo may come down to differences in opinion on how broadly the just war theory is meant to be applied.
“I think one of the ways to reconcile the disagreements between the president and the pope have to come down to whether criteria of Catholic just war … gets applied in the context of current global realities,” Gillespie said.