John Maynard Keynes was an economist and part of the Paris Peace Conference in 1919. He had high hopes for a new post-war order but when he realized what Georges Clemenceau, David Lloyd-George and Woodrow Wilson were planing, he resigned from the conference. And then wrote a book about it: The Economic Consequences of the Peace became a bestseller and is one of the best known critiques of the Versailles Treaty.
