If we are wrong, we will have destroyed a threat that, at its least is responsible for inhuman carnage and suffering. That is something I am confident history will forgive.

I mean, you can agree or disagree with Iraq or Afghanistan, but by the way, now the great campaigning cause out there is the absence of intervention in Syria. And then in Libya, it's partial intervention. And that doesn't really explain why some countries that have literally nothing to do with the interventions in the Middle East end up getting targeted.

Today the impulse towards interdependence is immeasurably greater. We are witnessing the beginnings of a new doctrine of international community.

I can only go one way. I've not got a reverse gear.

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.

I think what happened with 9/11 is that people sort of felt that it came from nowhere. Whereas I think now we understand the roots are very deep. I say it's like revolutionary Communism, something that is going to have to be knocked out over a very long period of time. This strain of extremism continues to be very strong, whether it's in Afghanistan, or Somalia or Yemen, or any of these places.

There is no way you're going to have an event like 9/11 and expect things to remain the same. They killed 3,000 people in New York on that day, and if they could have they would've killed 300,000.