The US war in Iran is on pause, at least of this writing. An unstable cease-fire could end next week with a resumption of hostilities—or, potentially, with the conclusion of this war. The one silver lining of a conflict initiated without a clear or consistent rationale is that it can wind down the same way.
But even if peace comes that soon, American Christians can’t pretend we haven’t seen what our leaders have done this spring. Ours is no longer a government interested in haggling over the finer points of just war theory, a Scripture-shaped standard of ethical conduct in warfare, to defend a military intervention. It is instead flirting with dispensing with that standard altogether, using the language and symbols of our faith while ignoring its substance.
For nearly all of American history, our presidents and their staff spoke of military decisions in language and reasoning deeply shaped by just war theory. An idea developed by Christian thinkers for centuries, the theory requires those who make war to assess its justice both before and during fighting. For a war to be just, theorists like Thomas Aquinas have argued, it must be waged by the right authorities for the right reasons and in the right way, particularly where innocent civilians are concerned.
Christian critics of the theory argue that its terms are too flexible and imprecise. For example, CT’s Bonnie Kristian has written that just war theory “can all too easily function less as a limit than as a malleable justification for whatever we’ve already decided to do.” And while the abuse of moral concepts does not invalidate their proper use, Kristian is correct to say that politicians have often employed the categories of just war theory in service of manifestly unjust wars.
That very malleability makes all the more shocking those moments when leaders don’t bother with just war theory at all—when they make no attempt at an ethical argument and instead explain their plans in nakedly immoral terms.
President Donald Trump took this path the day after Easter, when he announced on social media that “a whole civilization will die tonight, never to be brought back again.” This threat of death not only of enemy combatants but of an entire country is unmistakably a threat of genocide and a violation of the agreement against genocide the United States signed in 1948.
You don’t need an exhaustive knowledge of just war theory to know that genocide is well outside its bounds. This threat merits the most strident and serious moral condemnation, for the very act of threatening such profound evil trivializes that evil. And Iranian civilians had good reason to worry that this was not mere bluster, because that threat came as the culmination of a long train of disregard for both the principles of just war theory and US law.
After Trump himself, Secretary of Defense Pete Hegseth is the most prominent figure here. He speaks often of Christianity and has led prayer services at the Pentagon. In one of those meetings, Hegseth prayed for violence “against those who deserve no mercy.” At a press briefing in mid-March, he promised “no quarter, no mercy for our enemies.” And this past fall, Hegseth said that under his command, the armed services would be marked by “no more politically correct and overbearing rules of engagement, just common sense, maximum lethality and authority for warfighters.”
Though it’s certainly strange to invoke a “merciful and forgiving” God (Dan. 9:9) in support of one’s intention to deny mercy to others, there’s no legal definition of “no mercy.” The threat of “no quarter,” however, is a legal phrase. Under conditions of no quarter, defeated enemy combatants aren’t taken prisoner or offered the chance to surrender. They are simply killed.
Because soldiers who have surrendered are no longer combatants, their deaths are not the same as battlefield deaths. Killing them is murder—according not only to just war theory and the Hague Convention of 1907, which the US signed and ratified, but also to the Department of Defense’s own Law of War Manual. “It is forbidden to declare that no quarter will be given,” the manual says. “Moreover, it is also prohibited to conduct hostilities on the basis that there shall be no survivors, or to threaten the adversary with the denial of quarter.”
For US troops to follow through on Hegseth’s threat of no quarter would violate the Pentagon’s own rules. And, as scholar Oona Hathaway of Yale Law School recently noted, the declaration itself is wrong: It may make an enemy more likely to fight to the death and therefore make the battle more brutal than it needs to be.
Unfortunately, these comments are neither untypical nor unprecedented for Hegseth and the administration he represents. Hegseth came to Trump’s attention by lobbying for pardons and clemency for several US servicemembers for actions including killing former enemy combatants after they no longer posed a threat.
And last year, Hegseth dismantled the Pentagon’s Civilian Harm Mitigation and Response program, which was designed to prevent civilian casualties during American military interventions, acting over the objections of military officials including the chair of the Joint Chiefs of Staff. Since then, the preliminary findings of a Pentagon investigation reportedly say the US is likely responsible for the February strike on an Iranian girls school that killed at least 175 people, most of them elementary-aged schoolgirls.
Trump and Hegseth seem to want to wage war unencumbered by the task of protecting the dignity of human life. But that task is not about “politically correct and overbearing rules” or any other boogeymen of Hegseth’s imagination. Its source is the very Christian faith Hegseth has so often praised within the Pentagon. Just war theory is a distinctly Christian moral innovation that we must not discard.
Justin R. Hawkins is an ethicist and postdoctoral researcher at the Columbia University Irving Medical Center.
