By Natasha Lipman
BBC World Service
Why China's President Xi Jinping feels as insecure as his US counterpart
By Toby Luckhurst
Newsreel footage from 1945 shows Winston Churchill, Franklin Roosevelt and Joseph Stalin at Yalta.
Thirty years later, the author Kapka Kassabova, returns to the borders of her native Bulgaria
In 1961, Joachim Rudolph escaped from one of the world’s most brutal dictatorships. A few months later, he began tunnelling his way back in. Why?Copyright: BBC
By Gordon Corera
Hundreds of thousands of Soviet troops were stationed in the complex in former East Germany.
By Sanchia Berg
BBC Radio 4 Today programme