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.