For more than a year, the Obama administration has been assuring the world that the downfall of Syrian dictator Bashar al-Assad is “a matter of time.” Yes, its own Middle East experts warned, but how much time matters. The longer the fighting goes on, they said, the more likely it is that what began as a peaceful mass opposition movement would be hijacked by extremists, including allies of al-Qaeda.

President Obama ignored that advice, ruling out measures that could have quickly brought down the regime — such as a no-fly zone — in favor of a year of feckless diplomacy. But it turned out the experts were right. So now the consequence of Obama’s passivity has a name, one that will surely haunt the occupant of the White House in 2013: Jabhat al-Nusra.

. . . If the war drags on, Jabhat al-Nusra will surely grow stronger. It could begin to carve out a haven in the Syrian countryside where al-Qaeda operatives from around the region could gather. It could try to get hold of Syria’s abundant stocks of chemical weapons. And it could start looking beyond Syria for targets. You might say it’s a matter of time.