Criticising US Attacks on Iran, Pope Leo XIV: Not a Just War

Pope Leo XIV has asserted that the attacks launched by the US and Israel against Iran do not constitute a ‘just war’ because, in his view, the classical theory is no longer relevant to the realities of modern warfare.

“There is no just war there,” Leo told journalists during a flight from Rome to Madrid on Saturday (6/6/2026), marking his fourth overseas journey as Pope.

The Pope made these comments in response to questions from journalists regarding claims made by US Vice President JD Vance, who utilised the concept of a ‘just war’ to defend Washington’s military actions against Tehran.

According to Leo, the philosophical concept of a just war originated centuries ago, at a time when humanity could not yet imagine the massive destructive power of modern weaponry.

“The problem is that the theory of just war comes from centuries ago, from a time when people could not imagine the weapons and the capacity for destruction that exist today,” he stated.

This firm statement from Pope Leo extends the existing diplomatic rift and political tension between the Vatican and US President Donald Trump concerning the escalation of the conflict in Iran.