On June 28, 1919, the world's leaders came together in the Hall of Mirrors in the Palace of Versailles, one of the world's most opulent locales, to close the book on the First World War. The Treaty of Versailles has since been considered a massive failure, with Europe leading the world into another war just 20 years later. With the help of author Tim Cook, The Agenda looks at this historic treaty to examine what went wrong, what worked, and why it's more relevant than ever.