They did, in all their cowardly bravado, exactly what they claimed they would do.

Tuesday came the news of another horrifying beheading of a U.S. journalist by the Islamic State in Iraq and Syria (ISIS), a terrorist group and major combatant in Syria’s civil war that has recently captured large swaths of Iraq.  Steven Sotloff, a 31-year-old freelancer for Time magazine and other publications, was executed in a second snuff film posted by ISIS online in as many weeks. In it, a masked militant with a British accent stands over the kneeling Sotloff before killing him. “I’m back, Obama,” the fighter says, “and I’m back because of your arrogant foreign policy towards the Islamic State.”

He seems to be the same masked man who appeared in a video two weeks ago in which the American journalist James Foley was beheaded—retaliation for U.S. airstrikes in Iraq, so the killer said. The militant warned then that Sotloff, who was captured in northern Syria a year ago, would be next. This, despite a plaintive and heart-wrenching plea released last week by Sotloff’s mother, Shirley, who begged the head of ISIS to spare her son’s life.

And ISIS apparently isn’t done. It’s threatening to behead a third hostage–reportedly identified as David Cawthorne Haines, a British citizen– and is holding at least two other Americans captive.

We shouldn’t doubt the group’s intention to do extreme evil and boastfully broadcast it to the rest of the world. These are, after all, the same barbarians who have committed summary mass executions of civilians; crucified—quite literally—Christians and non-Sunni Muslims; rampaged through villages and cities. So why should they suddenly turn into reasonable, rational gentleman-and-professor-types and spare the lives of unarmed journalists who are simply trying to bear witness to a brutal conflict?

The Obama administration has said that ISIS is a cancer that must be cut out; it poses more of a threat to the U.S. than al-Qaeda. Something clearly must be done. Now might be the time to seriously consider arming the rebels who are affiliated with political moderates, an idea that has been kicking around Washington for a while. We’ve hesitated to do so for a couple of reasons: concerns about whom exactly to arm, about whether there are any good guys in this fight; and fear that we might somehow get dragged into yet another Middle Eastern war,

But ever since Foley’s beheading, there have been whispers that the U.S. may start cooperating in some manner with Syrian President Bashar al-Assad to try to wipe out ISIS. That would be unspeakable folly. The civil war in Syria began as a popular uprising in 2011 against Assad, who has ruled Syria with an iron fist for over a decade. (And his father before him, for almost three decades.) Assad hit back with relentless, pitiless force that ultimately pushed the protests into full-throttled rebellion, splintered along sectarian lines.

In response, the Syrian Air Force filled barrels with TNT and nails and oil and dropped the improvised explosive devices from helicopters—to devastating effect on the civilians below. It exploded Scud missiles in residential neighborhoods. Most horrifically, Assad launched several attacks of chemical weapons. (Which caught the world’s attention; after the U.S. threatened airstrikes, Assad agreed to have the stockpiles destroyed under international supervision.) The number of victims is breathtaking. Close to 200,000 people have been killed in the three-year-old conflict; 6.5 million Syrians are displaced from their homes; three million are living in squalid refugee camps in neighboring countries with little food or water.

Politics makes for strange bedfellows, but do we really want to be sleeping, however inadvertently, with Assad? This is a guy who gassed his own citizens. The Obama administration has publicly ruled out any sort of coordinated effort with him to defeat ISIS. But how else could we expand airstrikes from Iraq into Syria? President Obama is correct in carefully trying to choreograph an effect strategy, perhaps one that involves a broad coalition of countries. In a news conference on Wednesday, he said that if the U.S. were to be joined by the international community, it could continue to shrink ISIS’s “sphere of influence, its effectiveness, its financing, its military capabilities to the point where it is a manageable problem.” But without building up other rebel forces, taking out ISIS could have the unintended consequence of benefiting Assad.

Sotloff and Foley, with all the courage of their profession, went off to report on a war to overthrow Assad’s tyranny. They died because of it. What sad irony if their legacy is one that helps to strengthen the dictator’s grip on power.

Originally published by Thought Catalog at www.thoughtcatalog.com