There's no reason why Americans should die when Afghans are perfectly capable of defending their own country.

If we don’t uphold our Constitution and our values, that over time, that will make us less safe and that will be a recruitment tool for organizations like Al Qaeda. That’s what I have to keep my eye on.

I think the Turks' willingness to take seriously action on the borders to stop the flow of foreign fighters joining ISIL is significant.

I think it's fair to say that my temperament is steady - and on the buoyant side.

Our destiny is not written for us, but by us.

I do think that this whole area of cyber is something that at an international level we have to work on and develop frameworks and international norms so that we don't see a cyber arms race.

We will respond to the threat of climate change