The Economic Consequences of the by John Maynard Keynes was a best seller throughout the world and was critical in establishing a general opinion that the Versailles Treaty was a "Carthaginian peace". It helped to consolidate American public opinion against the treaty and involvement in the League of Nations. The success of the book established Keynes' reputation as a leading economist especially on the left. When Keynes was a key player in establishing the Bretton Woods system in 1944, he remembered the lessons from Versailles as well as the Great Depression. The Marshall Plan after Second World War is a similar system to that proposed by Keynes in The Economic Consequences of the Peace. John Maynard Keynes was a British economist whose ideas have profoundly affected the theory and practice of modern macroeconomics, as well as the economic policies of governments. He greatly refined earlier work on the causes of business cycles, and advocated the use of fiscal and monetary measures to mitigate the adverse effects of economic recessions and depressions. His ideas are the basis for the school of thought known as Keynesian economics, as well as its various offshoots.