Providence Magazine’s mission is to apply right-wing Christian ethics to matters of foreign policy. The magazine’s co-editor, Mark Tooley, writes he recently got into an argument about the ethics of America’s support for Saudi Arabia’s war in Yemen — the same war the U.S. Senate astoundingly rebuked this week — and concludes that Christian pacifists are morally unserious.

American Christian commentators can preach smug, condemning bromides. Or they can, if they are more serious, labor to apply the historical church’s vast ethical resources to complex geopolitical challenges for which there are usually no comfortable answers.

He doesn’t reference “just war” theory by name, though I assume that’s what he’s referring to. Technically, the theory is supposed to offer an obstacle to wanton warmaking — if you’re a Christian, you can only conduct a war under certain conditions — but I suspect that it doesn’t really work that way: Is there a war that America has refused to undertake because advocates conceded it didn’t meet just war criteria?

Let’s do what Tooley does, though, and apply the theory to Yemen. How does it stand up?

Just war theory is split into two parts — one that governs the reasons for going to war, the other that governs conduct in war. My friend Damon Linker one time summed up the six criteria for going to war thusly:

The war must be undertaken with the intention of establishing a just peace. It must be defensive. It must be aimed at protecting the innocent against unjust aggression. It must have a reasonable chance of success. It must be declared and waged by a competent governing authority. And it must be undertaken as a last resort. If the war meets these six criteria, it can be considered morally justified.

Let’s look at a couple of these items:

• It must be declared and waged by a competent governing authority.

How is such an authority defined? “A just war must be initiated by a political authority within a political system that allows distinctions of justice. Dictatorships (i.e. Hitler’s Regime) or a deceptive military actions (i.e. the 1968 US bombing of Cambodia) are typically considered as violations of this criterion. The importance of this condition is key. Plainly, we cannot have a genuine process of judging a just war within a system that represses the process of genuine justice. A just war must be initiated by a political authority within a political system that allows distinctions of justice.”

The war in Yemen being prosecuted largely by the kingdom of Saudi Arabia. It is a dictatorship — one that recently had an opponent living abroad assassinated and dismembered. There are few people outside Saudi Arabia who would argue the monarchy serves the cause of genuine justice.

• It must have a reasonable chance of success.

The war is nearly four years old. It is a stalemate. Everybody believes they can win a war at the outset. But at this point, any “reasonable chance of success” is remote. The longer a war drags on, the less justifiable it becomes under just war theory.

• It must be aimed at protecting the innocent against unjust aggression. 

The war in Yemen is mostly about geopolitical posturing by outside powers. You should read this easy explainer of the war if you don’t understand what’s involved, but here’s the key point for our purposes:

Alarmed by the rise of a group they believed to be backed militarily by regional Shia power Iran, Saudi Arabia and eight other mostly Sunni Arab states began an air campaign aimed at restoring Mr Hadi’s government. The coalition received logistical and intelligence support from the US, UK and France.

The innocent are neither here nor there, it seems. The old aphorism is that “war is politics by other means” and that seems to be the case here. You can think that Saudi Arabia is preferable to Iran. But that doesn’t conform to just war theory.

These are just the justifications for war. There’s also a set of criteria for how the war is conducted.

The big one, for our purposes is called “discrimination.” Basically, civilians aren’t combatants and thus should be spared the pains of war as much a humanly possible. And it’s here, perhaps, that the war in Yemen falls most disastrously short of being just.

From August:

GENEVA — The military coalition led by Saudi Arabia and the United Arab Emirates in Yemen has killed thousands of civilians in airstrikes, tortured detainees, raped civilians and used child soldiers as young as 8 — actions that may amount to war crimes, United Nations investigators said in a report issued Tuesday.

The report singled out Saudi and Emirati airstrikes for causing the most civilian casualties, saying they had hit residential areas, markets, funerals, weddings, jails, boats and medical facilities.

“There is little evidence of any attempt by parties to the conflict to minimize civilian casualties,” said Kamel Jendoubi, the chairman of the panel of experts that produced the report.

From November:

<p”>The announcement by Secretary of Defense Jim Mattis at the Pentagon came on the heels of a statement by the aid agency Save the Children on Wednesday that underscored the harrowing nature of the conflict: An estimated 85,000 children might have died of hunger since the bombings began in 2015.

Experts say Yemen has become the worst humanitarian crisis in the world, and 14 million people could soon be on the brink of starvation,according to the United Nations.

“For every child killed by bombs and bullets, dozens are starving to death — and it’s entirely preventable,” Tamer Kirolos, Save the Children’s country director in Yemen, said in the statement. “Children who die in this way suffer immensely as their vital organ functions slow down and eventually stop.”

I’m not as familiar with just war theory as I should be, admittedly. But it sure appears that even a cursory application of its principles finds the Saudi war in Yemen wanting — and thus the U.S. support of that war unjustifiable.

Mr. Tooley is right: The world is complex. Aphorisms don’t always match the complexity of a problem. But sometimes these matters are simpler than they seem. The war in Yemen is a moral disaster — truth, whether or not you bring the “historical church’s vast ethical resources” to bear, or not.