I think it's a mistake to rely too much on any one economic factor. It's why investors try to spread their portfolio round.

Islamic State is mainly a direct result of the failure in Syria. That's where IS has grown. That's where IS spread from.

The use of force to liberate people is very different from the use of force to suppress or control them, or even to defeat them.

I think it's a mistake to rely too much on any one economic factor. It's why investors try to spread their portfolio round.

Iraq has no history of ethnic conflict.

I mean, we're going to probably debate the Iraq war for at least as long as I'm alive.

The truth is that for reasons that have a lot to do with the U.S. government bureaucracy, we settled on the one issue that everyone could agree on, which was weapons of mass destruction, as the core reason.