The main theme of The Economic Consequences of the Peace is the harm that implementing the Treaty of Versailles (1919) after World War I would cause not only to Germany but to all of Europe. Because Keynes’s forecast—one of the earliest—on this subject turned out to be accurate in many ways, it is important to examine his arguments.

Keynes builds the case for continental European integration in every chapter of this book by using historical developments in the late 19th century, the technological advancements created by the two waves of the Industrial Revolution, the population growth, the logistical organization, and the reliance on importing resources and raw materials from the outside world such as the overseas European colonies. Russia can be excluded from this list because it was and remains a resource-rich country. Of course, the European economy of the late 19th and early 20th centuries was not integrated at the level of the 21st-century European Union and its single currency. However, continental Europe shared and continues to share many traits:

England still stands outside Europe. Europe's voiceless tremors do not reach her. Europe is apart and England is not of her flesh and body.