Saddam Hussein had nerve gas and used it against his own people, he had used chemical weapons against the Iranians and he almost had a nuclear bomb in 1981 and in 1991. And he had been caught with anthrax in 1995 by the UN inspections after denying that he had it.

I certainly think it's important to speak up and say how unacceptable Donald Trump is. I'm always more than willing to do that.

Every math curriculum in the world is based on the idea of hand-calculating, and most of what you're teaching is how to calculate. And I think the resistance to this is very variable.

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.

One of the things that ultimately led me to leave mathematics and go into political science was thinking I could prevent nuclear war.

If the Arab world today looked like Tunisia, it would be a huge blow for the extreme ideologies. But Tunisia needs more support than it is getting, particularly from their close neighbors in Europe who have a great stake in North Africa.

NATO is still the most remarkable alliance in history. It stuck together through 40 years of Cold War, and it then joined together to fight in Afghanistan. In the 1980s, I would not have thought this was going to be possible.