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.

For the private sector to flourish, special privilege must give way to equal opportunity and equal risk for all.

History is just littered with problems that were solved that were supposed to be impossible.

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.

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.

Our security depends on having good relationships with our allies. Donald Trump mainly shows contempt for them.

The Western alliance should have supported the Sunni opposition against the Assad regime from the beginning. As far as Iraq is concerned, if it had stayed stable the way it was in 2008, IS would not have been able to expand in Iraq the way they did. The mistake was that Barack Obama withdrew the armed forces from Iraq too fast.