The images were gutting. Silenced children and crushed families in the aftermath of Tuesday's deadly chemical weapon attack in Syria's Idlib province.

These are also the sorts of images that leave us repeating "never again," that all but audibly demand a more substantive response than words.

President Trump responded the following day with a 59-missile strike on a Syrian government airbase after announcing he was considering military intervention. The slaughter, which claimed more than 80 lives, was an "affront to humanity," Trump had said on Wednesday. "These heinous actions by the Assad regime cannot be tolerated."

Secretary of State Rex Tillerson said moves toward Syrian regime change are "underway."

The Trump administration's steps toward military intervention have received support from expected quarters. Sens. John McCain (R-Ariz.) and Lindsey Graham (R-S.C.) on Thursday called for the U.S. to ground the Assad regime's air force, while Sen. Tom Cotton (R-Ark.) made explicit his case for regime change. "Bashar al-Assad must ultimately go," he said, suggesting a large-scale invasion of Syria may be necessary because "we cannot be safe as long as the Assad-Iran-Russia axis is in charge" in Damascus.

On the other side of the aisle, Democratic congressional leaders (implausibly, given this administration's escalation in Syria) criticized Trump for putting the U.S. on the "sidelines," suggesting his overtures to Assad's allies at the Kremlin enabled this attack. Now, they argued—differing in tone but not in goal from their GOP counterparts—it is time for the U.S. via the U.N. to intervene.

Missing in all this is even a trace of realism and reason.

The impulse to intervene is more than understandable in the face of such violence, but if the last decade and a half of foreign policy failures tell us anything, it is that the road to Raqqa is paved with good intentions.

A well-meant desire to insert the full might of the American military into the chaos of Syria is no guarantor of successful regime change. No serious person can promise such a simple triumph, not now, 14 years after our intervention in Iraq and ouster of another cruel and ostensibly secular Mideast dictator. As much as we might wish it, U.S. intervention cannot even bring the promise of fewer civilian casualties than would accrue without our presence. And the lesson of the rise of the Islamic State in Iraq and Libya is that a U.S.-fostered power vacuum may even make Syria's suffering worse.

Beyond these heavy practical considerations are issues of grand strategy and legality. As Michael Brendan Dougherty notes at The Week, the primary question we must ask after the Idlib attack is not "'Must this be stopped?' We know the answer to that question: Of course it ought to be."

No, the primary question, the conservative columnist correctly argues, is should "the emotion generated by these pictures elicit our consent for the United States military, under President Trump, to intervene even more aggressively on behalf of al Qaeda in Syria, under the legal authority of a 2001 act of Congress declaring war on al Qaeda?"

This is, in practice if not in rhetoric, what the bipartisan Washington establishment has hurried to demand. Regime change in Syria as currently conceived is an executive war of choice, launched without constitutionally-mandated congressional authorization and serving as de facto assistance to rebel groups marked by their uncertain ideology and shadowy ties to the perpetrators of 9/11.

We need not concede an inch of moral approbation to the Assad regime to recognize these very real complications the regime change narrative ignores. Trump once made that distinction himself. "What will we get for bombing Syria besides more debt and a possible long term conflict?" he asked on Twitter after a far deadlier chemical weapons attack in 2013. "Obama needs Congressional approval" for military intervention, he added.

Trump was right on both counts: What is happening in Syria is appalling, but that does not mean U.S. military intervention is the prudent response for America or Syria. As things now stand, there are simply too many unanswered questions and unaddressed risks. The likelihood of long-term occupation and stymied nation-building, as well as the possibility of mission creep into armed conflict with Iran or Russia, are chief among them. Does anyone believe Syrian civilians will be safer if their country becomes a theater of U.S.-Russian war?

Trump in 2013 was right about congressional approval, too, and he must subject himself to the legal limit he sought to impose on his predecessor.

There is no coherent case to be made that war on the Assad regime is in any way permitted by the 2001 or 2002 Authorizations for Use of Military Force (AUMFs) already stretched too thin to justify current U.S. actions in Afghanistan, Iraq, Libya, Pakistan, Somalia, Syria (against ISIS), and Yemen.

If President Trump wants to launch what is indisputably a major new war, he must do so only at congressional debate and behest.

There is no easy fix for Syria's tumult and misrule, contrary the facile rush to war with which much of Washington has responded to this new chemical attack. Rash reaction may be tempting, but prudence demands we learn from foreign policy mistakes past to avoid yet another headlong sprint into what is certain to be a costly, lengthy intervention that may—for all involved—do more harm than good.

Photo Credit: Polaris/Newscom