Barack Obama actually said...

The United States is acting and leading, and the world cannot sit by and watch innocents die.

I will just note for people in case it's of interest, as I said, he had several check-ins with his national security team today.

As commander-in-chief, I will not allow the United States to be drag into fighting another war in Iraq and so, even as we support Iraqis as ...

We will take action. That is our responsibility as Americans, it's whole mark of American leadership.