He said this at the G-7, after visiting a memorial to victims of a Nazi atrocity, so take that however you like. Maybe he was moved by the occasion to this rhetorical flourish, which he has no intention of actually heeding in his official duties — or maybe Assad’s gassing in Idlib really did cause a sea change in the administration’s thinking about humanitarian intervention and he has every intention of heeding this in his official duties. Offhand I can’t recall Obama ever saying something quite this sweeping about punishing human-rights violators for oppressing the innocent. It’s straight out of Bush’s second inaugural address.

We’ll find out soon if he’s serious. Some observers expect Assad to get even nastier in Idlib province, site of last week’s apparent sarin attack:

“Assad’s plan was to gather all the fighters, to push them away from their towns and make them gather in Idlib and that was on purpose,” he said. “Assad’s plan is to urge the international community and the United States to kill these people.”…

Aid groups warn that up to 1.5 million civilians could face a humanitarian catastrophe in Idlib if the Assad regime begins bombarding the province on a large scale, causing a huge flow of refugees into Turkey and Europe and resulting in devastation and suffering on a scale many times greater than what was seen during last year’s siege of Aleppo…

Stretched thin after six years of war, the Syrian army cannot take Idlib through conventional means. That’s why Assad is using weapons of terror, such as nerve gas, to break the will of the civilians before the battle there begins in earnest. When the ground war erupts, a thick stew of Shiite militias, Hezbollah fighters, Afghan mercenaries and Iranian Revolutionary Guard soldiers, all covered by Russian air power, will be ready to take on the regime’s adversaries.

That’s one theory for why Assad used gas. Another theory is that he was spooked by gains made late last month by the rebels in a different province, Hama, where they threatened to seize a key government airfield used for barrel bombs. Both theories agree, though, that regime forces are thoroughly exhausted, relying on demoralized conscripts; Assad’s infantry power at this point consists mostly of foreign militias. Air attacks involving barrel bombs and nerve gas appear to be among the few means left to him to assert some direct control over the battlefield. Go figure then that he’d resort to WMD to try to terrify the enemy into submission, knowing he no longer has the military means to make them submit.

Exit question: Will we be holding Kim Jong-un to account for his many, many crimes against innocents too? Or does “hold to account” here include mere rhetorical reprimands, like disapproving State Department statements?