In 2012, President Obama warned that Syrian President Bashar Assad’s use of chemical weapons was a “red line” that would “change (the) calculus” of U.S. policy toward the Syrian civil war. A year later, faced with evidence that Assad had used sarin gas against his own people, Obama said, “The use of chemical weapons anywhere in the world is an affront to human dignity and a threat to the security of people everywhere.” President Trump apparently agrees: He ordered a missile strike against the Shayrat air base in Syria in early April, in retaliation for another chemical attack.

The Obama-Trump doctrine that the United States will enforce a global norm against the use of chemical weapons is strategically pointless and morally arbitrary. Strategically, it requires the United States to invest its time and resources policing a weapon this is not qualitatively different from conventional weapons. Morally, it amounts to a declaration that the United States cares more about the murder weapon than the murder victim.

Despite their reputation, chemical weapons are not especially deadly or efficient at killing people compared to conventional weapons. Chemical weapons saw their widest use in World War I, during which they killed relatively few soldiers: perhaps 90,000 out of up to 17 million people who died during the war. Chemical weapons sickened tens of thousands more, most of whom recovered.

So why do we blame chemical weapons for the carnage of World War I? The weapons were new and poorly understood – soldiers naturally feared them. They were also viewed as ungentlemanly, a form of unchivalrous cheating – a special kind of insult for professional soldiers. The reputation of chemical weapons doubtless helped bring about strict regulations on them after the war. But the true weapon of mass destruction in World War I was the machine gun, followed by influenza.

Iraqi dictator Saddam Hussein notoriously used chemical weapons against Kurdish civilians in Halabja in 1988, an attack that probably killed around 5,000 people. But the attack involved at least a score of aircraft flying a dozen or more sorties dropping bombs for hours, preceded and followed up by conventional explosives. Given that much firepower and time, Saddam Hussein could have killed as many – probably more – with any kind of explosive. Saddam Hussein discovered, as others have before, that chemical weapons are difficult to employ because they depend on ideal weather conditions beyond human control. Since chemical weapons are costly to build and maintain safely but not terribly useful, it was easy for the great powers to ban them entirely after the Cold War.

Morally, there is no point whatsoever to enforcing a global ban on the use of chemical weapons. I am not arguing we should be more permissive about their use; rather, I am arguing we should be far less permissive about the slaughter of civilians, regardless of the weapon used. The Trump-Obama doctrine amounts to a declaration that the dictators and tyrants of the world can murder their citizens with impunity so long as they dare not murder with a chemical weapon. It signals that perpetrators of genocide enjoy a free-fire zone within their own countries if they pretend to keep the killing clean and gentlemanly.

If you think there is really such a thing as clean and gentlemanly killing, you have watched too many war movies. As Gen. William Sherman reputedly said, “I am tired and sick of war. Its glory is all moonshine. It is only those who have neither fired a shot nor heard the shrieks and groans of the wounded who cry aloud for blood, for vengeance, for desolation. War is hell.” Or as Dwight D. Eisenhower said: “I hate war as only a soldier who has lived it can, only as one who has seen its brutality, its futility, its stupidity.”

War is always barbaric and obscene, even just war. It is morally obtuse to believe that there is such thing as clean or humane killing. I am no pacifist: I am a veteran of the war in Afghanistan and I believe there is an occasion when the use of force is just. But I am under no illusion that killing is ever gentlemanly or clean. Pretending that there is a humane way to kill someone is ridiculous – it is in fact immoral, because it allows deluded civilians to support war under the false pretense that it is more humane than it actually is. Dead is dead, whether killed by bomb, bullet, or machete.

Enforcing a ban on the use of a certain weapon places moral weight on the wrong thing: on the weapon rather than the purpose for which it is employed. We should be angered at the massacre of civilians, regardless of the method of their deaths. If Assad was a monster for gassing a few dozen people this month, he was a monster for slaughtering 500,000 over the past six years with barrel bombs and conventional explosives. It takes a striking degree of moral myopia to be angrier about the murder weapon employed than the fact of the murder in the first place.

I understand that photos of dead Syrian children who were gassed to death troubled many people, including the president. “A chemical attack that was so horrific in Syria against innocent people including women, small children, and even beautiful little babies – their deaths was an affront to humanity. These heinous actions by the Assad regime cannot be tolerated,” Trump said in response to the chemical attack in early April.

But if you want to base your foreign policy on troubling photos, you have just outsourced your grand strategy to CNN – or worse, Twitter. You are creating a norm that if you want America’s attention, be sure to capture your victimhood on camera. The Afghans, for one, might feel justifiably jilted that the world’s media decamped from Kabul long ago, leaving so many useful atrocities unfilmed.

And, finally, you need to recognize that the Syrian photos weren’t even that bad on the scale of world events. If you felt the warm glow of virtuous anger at Assad after viewing those pictures, you need to Google the Rwandan genocide, or the massacre at Srebrenica, or perhaps Auschwitz. Be sure to sit down, don’t eat, and turn SafeSearch off.

Paul D. Miller is the associate director of the Clements Center for National Security at The University of Texas at Austin and a research fellow at the Ethics and Religious Liberty Commission. He served as director for Afghanistan and Pakistan on the National Security Council staff under Presidents George W. Bush and Barack Obama.