Thanks, David. That's all the time we have for this round.
Before we start the next round I do want to ask a question, probably a quick question that requires a longer answer.
Can we talk a bit about Iran? I know that Iran has been a hugely destabilizing force in the area, in Syria as well as Iraq. They're concerned with ISIL. From a security perspective, how do you see dealing with Iran as it relates here? It's obviously a very tricky question. They've not had a great track record at all in this area.