The moral authority of pontiffs has long been used to cajole world leaders into peace and reconciliation. Earlier this year, for instance, Pope Francis tried to restart talks between Israel and the Palestinian Authority with a prayer service that included Shimon Peres and Mahmoud Abbas.

That tradition of papal peace-making lends even more weight to the remarks this week from Pope Francis on the threat of ISIS and the genocide in Iraq and Syria. Talking with the press on his plane as it left South Korea, the pope warned that "unjust aggression" had to be stopped and that action from the international community would be "legitimate." The Associated Press immediately ran the remarks with a headline announcing that the pope had endorsed the use of military force against ISIS, later changing it to "Pope Oks Protecting Iraq Minorities." Reuters' story carried the banner "Pope says legitimate for world to stop Islamist aggression in Iraq."

Has the Vatican abandoned pacifism? Not exactly. While Vox and others hyperbolically suggested that Francis had issued a call for a new crusade, the pontiff hardly asked for a Western campaign of conquest. Francis' remarks fall within what could be called a tradition of conditional pacifism, one that recognizes the limits of dialogue and negotiation in the prosecution of violent evils such as genocide. Francis seeks the restoration of peace, which on occasions means the use of force for that purpose — and that purpose only.
It may come as a surprise to many that the Catholic Church still adheres to the "just war" doctrine, which applies to the gap left when negotiation and dialogue either fail or have no rational application. The Catechism, which outlines the application of Catholic faith in the world, expressly notes the circumstances in which this occurs, as well as the strictures for operating within Christian morality when it occurs. For armed resistance to have moral legitimacy, it has to meet five conditions set out in paragraph 2243:

(1) there is certain, grave, and prolonged violation of fundamental rights; (2) all other means of redress have been exhausted; (3) such resistance will not provoke worse disorders; (4) there is well–founded hope of success; and (5) it is impossible reasonably to foresee any better solution.

Few would doubt that the situation in northern Iraq meets the first condition, and the proclaimed commitment by ISIS to genocidal policies such as murder, rape, and displacement offer no rational options for the second. One shudders to imagine a worse outcome than the present for the Yazidis, the Christians, and the heterodox Muslims facing annihilation or slavery, so the third condition is almost a moot point.

That leaves us with the fourth and fifth conditions for armed resistance (and by extension, armed intervention). One can argue that it's so impossible to see a reasonable alternative to armed intervention because there isn't much hope of success even in that direction, but those two points are the most debatable of these conditions. To shrug off any responsibility on the basis of difficulty, however, is to condemn thousands of people in Iraq to slavery — or worse — under the brutal and evil reign of ISIS and their self-proclaimed caliph, Abu Bakr al-Baghdadi.

Francis called on the world to commit to stopping this evil, first by having the debate over all these points in the proper forum. "A single nation cannot judge how to stop an unjust aggressor," Francis told reporters, noting that the victorious powers of World War II set up the United Nations to mediate these very matters. That, the pope said, "is where it must be discussed and asked, 'Is there an unjust aggression?'" and, if so, 'How do we stop it?'"

Still, to ask those questions is to almost beg the answer in this extreme circumstance. That is why, as Vatican reporter John Allen noted at The Boston Globe, Vatican officials had already gone on the record with approving comments for the ongoing military intervention by the U.S. Allen cautions that Francis' direct remarks still amount to a yellow light rather than a full-throated endorsement for military intervention.

However, it is clear that Francis wants the world to do something to stop the ongoing massacre of civilians in northern Iraq. The pope told reporters he'd even considered going to the region himself to force attention to the ghastly crisis unfolding there, but thought better of it. The Vatican has warned for months about the disaster of ISIS and the indications of slaughter and oppression, to little notice and less avail. The U.S. has belatedly begun an intervention to protect the Kurds from being overrun, but few other nations have done much else, and the world community has still not addressed this in a cohesive and unified manner.

So yes, it's surprising to hear a pope raise the possibility of a moral armed intervention. But the bigger surprise is that the pope had to raise the possibility himself while the rest of the world is pretending not to notice.