Anne Applebaum, the Pulitzer prize-winning author of 'Gulag', discusses her new book, which explores the historical, political and moral forces at work behind the Iron Curtain.

In 'Iron Curtain - The Crushing of Eastern Europe, 1944-56' Applebaum has produced an account of a brutal period of European history. She offers a startling reminder of how fragile free societies are, and how vulnerable they can be to determined and unscrupulous tyrants.

In association with The Economist.