Pope Leo says US-Israeli war against Iran fails 'just war' test

Papal rejection of 'just war' doctrine

Pope Leo XIV declared on Tuesday that the military campaign waged by the United States and Israel against Iran does not qualify as a "just war," telling journalists aboard his flight to Madrid that centuries-old theological theories cannot account for modern weapons of mass destruction. Speaking during the fourth foreign trip of his pontificate, the pontiff dismissed arguments by US Vice President JD Vance, who had invoked the just war concept to defend Washington's strikes on Tehran, stating bluntly that "there is no just war there."

"The problem is that the just war theory comes from centuries ago, from a time when people could not imagine the weapons and destructive capacities that exist today," the pope added, according to Vatican press pool reports. His remarks came as the conflict entered its latest phase, with the Holy See maintaining its consistent stance that diplomatic solutions remain the only legitimate path toward regional stability.

Escalating Vatican-White House tensions

The pope's comments deepen a public rift with US President Donald Trump, who earlier this year threatened that "there will be no civilization left in Iran" — a remark Pope Leo promptly condemned as unacceptable rhetoric that could fuel further escalation. Trump responded by calling the religious leader "weak and terrible on foreign policy," prompting the pontiff to reject the criticism and affirm he would continue speaking out against the violence without fear of political backlash.

Rome rallies behind pontiff

The exchange drew swift support for the pope within Italy, where Prime Minister Giorgia Meloni described Trump's personal remarks targeting Pope Leo as "unacceptable" and voiced solidarity with the Vatican's peace initiative. Political leaders across Rome emphasized the moral authority of the Holy See as fighting continued to claim civilian casualties in the region.