When I had my first day as the spokesman of NATO many years ago, the secretary general at the time, Jaap de Hoop Scheffer, said, “Okay, here are your instructions: never answer a question that begins with 'if'.” I never did, so I won't start now.
I can say that based on what you see in the Security Council, that's not a very likely scenario. Second, NATO is not getting involved in any way in the Syria crisis at present. But in a more generic sense, I don't want to leave the impression that the U.S. couldn't command very large operations ad infinitum. They could do it forever. But once you move beyond the U.S., there is no other way to generate and sustain a large multinational operation. That's what I was trying to imply by that.
If there is a consensus in the UN Security Council that NATO should do something, considering the deep commitment of all 28 allies to the UN and the fact that we have three permanent members of the Security Council in NATO, it would be looked at very carefully.