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 want my son to grow up in a place where the people are more powerful than the government and not the other way around.

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.

My course has never been about triangulation, and neither, really, is Bill Clinton's. It's not - it's about applying your values to the future in a practical and unblinking way, and that is an ideological view that is every bit as strong as views from the left or from the right.

People divide into groups where they talk to each other, but don't talk across the divide. And yet most of the challenges we face in the world today are challenges that are to do with trade, with technology, with how you make sure that people are properly educated, reform your health care system.

I have absolutely no doubt at all that we will find evidence of weapons of mass destruction programmes.

And just as the terrorist seeks to divide humanity in hate, so we have to unify it around an idea. And that idea is liberty.