After the Berlin Wall came down I visited that city and I will never forget it. The abandoned checkpoints. The sense of excitement about the future. The knowledge that a great continent was coming together. Healing those wounds of our history is the central story of the European Union.

Half a century ago, the amazing courage of Rosa Parks, the visionary leadership of Martin Luther King, and the inspirational actions of the civil rights movement led politicians to write equality into the law and make real the promise of America for all her citizens.

Yes, America must do the right thing, but to provide moral leadership, America must do it in the right way, too.

Today, hundreds of millions dwell in freedom, from the Baltic to the Adriatic, from the Western Approaches to the Aegean. And while we must never take this for granted, the first purpose of the European Union - to secure peace - has been achieved and we should pay tribute to all those in the EU, alongside Nato, who made that happen.

I don't just want a better deal for Britain. I want a better deal for Europe too. So I speak as British prime minister with a positive vision for the future of the European Union. A future in which Britain wants, and should want, to play a committed and active part.

We believe in a flexible union of free member states who share treaties and institutions and pursue together the ideal of co-operation, to represent and promote the values of European civilisation in the world, advance our shared interests by using our collective power to open markets, and to build a strong economic base across the whole of Europe.

It does not seem to me that the steps which would be needed to make Britain - and others - more comfortable in their relationship in the European Union are inherently so outlandish or unreasonable.

I think we need to just be very clear about what we're trying to do in Afghanistan. Frankly, we're not trying to create the perfect democracy. We're never going to create some ideal society. We are simply there for our own national security.

The political system is broken, the economy is broken and so is society. That is why people are so depressed about the state of our country.

I have no time for those who say there is no way Scotland could go it alone. I know first-hand the contribution Scotland and Scots make to Britain's success - so for me there's no question about whether Scotland could be an independent nation.