The Syrian civil war has been a nonstop horror show not only for the people of Syria and their neighbors but also for the United States. After setting up an Atrocities Prevention Board and vowing to stop crimes against humanity, President Obama has done essentially nothing even as the civil war has consumed more than 200,000 lives and displaced more than half of the population. American neglect has allowed the country to be divided between Iranian-backed Shiite extremists such as Hezbollah and Sunni extremists such as the Al Nusra Front and ISIS. Amid this parade of atrocities, virtually the only thing that Obama could boast of was that he had engineered, along with Vladimir Putin, a deal to take away Bashar Assad’s chemical weapons.

If so, then why is there credible evidence that the Assad regime has been dropping chlorine gas on civilians in recent days? As Josh Rogin of Bloomberg notes, “Unfortunately, chlorine, which has non-military uses, was not part of that deal. Assad has flaunted the loophole.” The fact that chlorine was not included was bizarre; it is the original chemical weapon, having first been used at the Battle of Ypres in 1915.

But the UN Security Council has acted to erase the loophole. On March 6, the Security Council passed a resolution condemning the regime’s use of chlorine gas after concluding “with a high degree of confidence that chlorine has been used repeatedly and systematically as a weapon in the Syrian Arab Republic.” The Security Council members stressed “that those individuals responsible for any use of chemicals as weapons, including chlorine or any other toxic chemical, must be held accountable.”

That would seem to present yet another “red line” that the administration can either enforce or ignore. Opposition activists believe that Assad is once again testing the international community with a series of small attacks utilizing chlorine gas to see how they react. He did the same thing with sarin gas, and when he found little resistance in the world, he unleashed an attack in August 2013 that killed 1,400 people. If left unchecked, we can expect to see chlorine gas employed on an even bigger and deadlier scale, along of course with barrel bombs and other favored instruments of mass destruction employed by the Assad regime and its Iranian patrons.

It will be fascinating to know what if anything the administration will do about this—just as it would be fascinating to know what the administration plans to do to dislodge either ISIS (which it has pledged to defeat) or Assad (whose downfall it once advocated). Secretary of State Kerry who called this week on Assad to get involved in negotiations with the U.S. probably delivered the answer. If only hot air could somehow be utilized as an effective antidote to poison gas.