The Washington Post's Louisa Loveluck reports on the regional reaction to President Trump's cruise missile strike against a Syrian airfield in response to a chemical attack that killed dozens of civilians. (Louisa Loveluck, Jason Aldag/The Washington Post)

Allow me to ask an uncomfortable question: If you were in a war zone, and the government dropped a bomb on your house that killed your entire family, would you say, “It could be worse — at least they weren’t killed with chemical weapons”?

I ask that question because while opinions differ about the wisdom of President Trump’s decision to launch missiles at a Syrian military base in retaliation for Bashar al-Assad’s chemical weapons attack on civilians this week, no one questions the idea that chemical weapons are uniquely heinous. There seems to be widespread agreement that their use constitutes justification for military action against the perpetrators, even if you happen to think that this particular military action is a bad idea.

But is that true? When you try to articulate exactly why chemical weapons are worse than conventional weapons, you realize that it’s hard to come up with a compelling explanation for treating them differently.

Think about it this way. Since the Syrian conflict began in 2011, Assad has killed hundreds of thousands of civilians; a year ago, one estimate put the death toll at 470,000. The vast majority of them were killed with bombs and bullets. Trump’s belief up until now was that those deaths, as regrettable as they might be, were not enough to justify U.S. military action against the Syrian government.

But now everything has changed. Why? Because, we’re told, Assad used chemical weapons (not for the first time, but for the first time since Trump became president), and that is a step too far. Furthermore, it was the images of children killed with chemical weapons that supposedly sent Trump over the edge. The New York Times reports: “This time, though, a new American president was seeing the pictures and absorbing the horror.”

Just look at how Trump described it on Wednesday: “When you kill innocent children, innocent babies — babies, little babies,” he said, “that crosses many, many lines, beyond a red line. Many, many lines.” But it’s not as though he just found out that children are dying in Syria.

We get to see those horrifying images precisely because they are less gruesome than what happens when someone is killed by conventional weapons. If a photojournalist takes a photo of a dead child whose limbs have been blown off by a bomb, you won’t ever see it (and neither will Trump). The newspaper won’t run it, and the evening news won’t show it, because editors consider those images too upsetting. But you will see a photo of a child killed by sarin gas, because her body is intact. The spread of those images will then reinforce the idea that these chemical weapons are worse than the conventional weapons that have killed many more in this war.

So, to repeat: Why are chemical weapons worse? We often group them in the “weapons of mass destruction” category along with nuclear and biological weapons, but that doesn’t make much sense. Nuclear weapons are bad because they can kill enormous numbers of people, into the hundreds of thousands or even millions, all at once. Biological weapons are bad because, once deployed, they can spread out of control, killing untold numbers of noncombatants. We’ve tried to ban landmines because they remain active long after a conflict is over, killing innocent people years or even decades later. None of those concerns really applies to chemical weapons.

If it’s just that chemical weapons can kill lots of civilians, that certainly applies to conventional weapons as well. And the moral case against Assad would seem to lie more strongly with the half a million people he killed before this week than the 100 or so he killed in Khan Sheikhoun.

To be clear, I’m not arguing that every country should start producing, stockpiling and using chemical weapons. But the most coherent argument I’ve seen in favor of the taboo on chemical weapons is the somewhat tautological one that the taboo has succeeded in forestalling the use of chemical weapons. Fair enough, but that hasn’t done much to affect the ability of dictators and warlords to kill as many civilians as they like. Assad is doing quite a fine job massacring people with conventional arms — and he’ll continue to do so.

I could offer any number of theories for why the world treats chemical weapons as outside the bounds of the moral conduct of war, but I suspect it may have its roots in ideas about the warrior’s honor. It was considered honorable to thrust your sword into an opponent while you looked him in the eye, but not to poison him; the scope of honorable means of killing was later widened to including shooting and bombing (though when aerial bombing emerged as a weapon in the early 20th century, some considered it barbaric). But the fact is that the taboo against the use of chemical weapons exists; indeed, the best explanation for why Assad conducted this attack lies in its symbolic value, that it would show his enemies that his savagery is boundless and they should abandon all hope of defeating him.

I don’t believe for a minute that Trump, a man who has never demonstrated an iota of human empathy, actually decided to launch this attack because he was so moved by the thought of children being killed. I suspect it had much more to do with his desire to look strong and, above all, do something different from what Obama did. Nevertheless, the attack has reinforced the chemical weapons taboo. That in itself isn’t a bad thing for the world at large, but it doesn’t achieve very much. It would not be at all unreasonable for Assad to conclude that as long as he keeps killing civilians only with conventional weapons (and executing them by the thousands in his prisons), he’s free to carry on.

And that’s just about the best-case scenario that will emerge from this U.S. attack. If Assad doesn’t use any more chemical weapons, will we consider that a victory?

Trump has long held that the United States shouldn’t try to overthrow Assad, and there are lots of people on both the right and left who agree, since doing so would either create a vacuum in which a radical jihadist group might take power, or require a long, bloody and expensive occupation along the lines of what we went through in Iraq. But what’s Trump’s plan now? He has shown that he’ll lob some missiles at a military base in defense of the principle that no one should use chemical weapons. If Assad complies, what then? Does Trump even have a vision for what he’d like to see happen in Syria, let alone what the United States might do to help that result come to pass?

There’s no evidence that he does. So now we can say that as a nation we stood up against chemical weapons — and accomplished virtually nothing.