intended to show that Germany had conducted a defensive war. On 16 June 1919, Georges Clemenceau, the French president, presented an ultimatum to Germany—if it did not accept the peace treaty, war would recommence—and on 28 June 1919 Germany accepted the Versailles Treaty. The immediate need to refute war guilt was replaced by a long-term project agreed by Cabinet on 21 July 1919 to shift attention from war guilt to a debate about European affairs since 1870. This project had three editors: Mendelssohn-Bartoldy, Lepsius, and Thimme (Director and "special advisor". The German Foreign Ministry directed the editors on how and what to publish and exercised a special veto. The result was the 40 volumes of Die Grosse Politik der Europäischen Kabinette 1922-27, which became the standard work of reference for the German view of World War I. History To disseminate the government's official position, several "independent" bureaux and journals were established, and many writers were paid for articles of a refutational nature. Besides a wide range of effort to promote its position, works of sympathetic writers were translated into a number of languages and disseminated at government expense, and visits by such writers were also paid for. As part of this effort, the Centre for the Study of the Causes of the War (Zentralstelle zur Erforschung der Kriegschuldfrage (ZEK)) was founded in 1921 under a Swiss doctor, Ernst von Sauerbeck, and from 1923 under Alfred von Wegerer. Harry Elmer Barnes, an American, who between World War I and World War II was a well-known anti-war writer, a leader in the historical revisionism movement and later to become a Holocaust denier, and from 1924 onwards worked closely with the Centre for the Study of the Causes of the War. The Centre provided Barnes with research material, made funds available to him, translated his writings into other languages, and funded his trip to Germany in 1926. During Barnes's 1926 trip to Germany he received a most friendly welcome for his efforts as Barnes described it in "seeking to clear Germany of the dishonour and fraud of the war-guilt clause of the Treaty of Versailles". The mission of the Centre became increasingly irrelevant as it was subsumed into the official position of the Nazi government after 1933, and especially after Hitler's revocation of Germany's signature on the Treaty of Versailles in 1937. See also Causes of World War I Color book War guilt