The threat today is not that of the 1930s. It's not big powers going to war with each other. The ravages which fundamentalist political ideology inflicted on the 20th century are memories. The Cold war is over. Europe is at peace, if not always diplomatically.

But I am an optimist about Britain; and the difference between an optimist and a pessimist is not that the optimist believes the world is wonderful and the pessimist believes it's beset by challenges; the difference is the pessimist believes we will be defeated by them; the optimist thinks the challenges can be overcome.

Human progress has never been shaped by commentators, complainers or cynics.

It's not that tens of millions of people all want to be violent. But they share the worldview that then, at its extreme, gives rise to the violence. And in my view, this is why this is such a global problem.

I just want to say this. I want to say it gently but I want to say it firmly: There is a tendency for the world to say to America, ‘the big problems of the world are yours, you go and sort them out,’ and then to worry when America wants to sort them out.

I haven't come to the conclusion that centrist politics is wrong or dead. On the contrary. I think it's very much alive - but it needs to be given a renewal, a revival, and a muscularity which it presently lacks.

There's a deep affection and respect for the Queen and the monarchy in the U.K. But Diana was an extraordinary, iconic figure and her death sparked a fierce reaction, part grief and part anger at her being taken away. It was very fraught.