For months warnings have sounded over the rising threat posed by extremists operating unimpeded in Syria. Now those fighters are cutting their way through Iraq and plunging the region into a sectarian bloodbath with consequences that would stretch well beyond the Middle East.
So exactly where do the ambitions of the Islamic State in Iraq and the Levant, or ISIL end? And can a United States entering an era of curbed enthusiasm for foreign interventions succeed in rallying the resources required to counter them?
For those who have long argued that America needed to weigh the costs of inaction in Syria and the very real risk of creating a bullpen for extremists in the country, the ISIL surge in Iraq is cause for very serious concern.
"This is a strategic development, not a tactical development, because this is a group that has lots of money and lots of arms and an image of success they are trading on right now," former Ambassador Dennis Ross told Defense One. "Ultimately what they want to do is show how they are able to take us on. And so we will be drawn into this more and more inevitably because we will have to interrupt their ability to plan and operate lest they become a threat to us."