foreign policy at that particular time. In Mayer's opinion, the "New Diplomacy", associated with Lenin and Wilson, was associated also with Russia and America, both societies that Mayer has argued either had destroyed or lacked the partial "modernized" societies that characterized the rest of Europe. He sees the United States' diplomacy at Versailles as an attempt to establish a "new", but "counter-revolutionary" style of diplomacy against "revolutionary" Soviet diplomacy. Mayer's opinion is that the greatest failure of the Treaty of Versailles was that it was a triumph for the "Old Diplomacy" with only minor elements of "New Diplomacy". According to Mayer, the irrational fears generated by the Russian Revolution resulted in an international system designed to contain the Soviet Union. A major influence on Mayer was the British historian E. H. Carr, who was his friend and mentor. In 1961, Mayer played a major role in the American publication of Carr's book What Is History? Many of Mayer's writings concerning international affairs during the interwar era use the assumptions of Carr's 1939 book The Twenty Year's Crisis. In his 1981 book, The Persistence of the Old Regime, Mayer argued that there was an "umbilical cord" linking all events of European history from 1914 to 1945. In Mayer's opinion, World War I was proof that "[t]hough losing ground to the forces of industrial capitalism, the forces of the old order were still sufficiently willful and powerful to resist and slow down the course of history, if necessary by recourse to violence." Mayer argued that because of its ownership of the majority of the land in Europe and the middle class were divided and undeveloped politically, the nobility continued as the dominant class in Europe. Mayer argued that challenged by a world in which it was losing their function, the aristocracy promoted reactionary beliefs such as those of Friedrich Nietzsche and Social Darwinism, together with a belief in dictatorship and fascist dictatorship in particular. In Mayer's opinion, "It would take two world wars and the Holocaust […] finally to dislodge the feudal and aristocratic presumption from Europe's civil and political societies." In his 1988 book Why Did the Heavens Not Darken?, Mayer argues that Adolf Hitler ordered the Final Solution in December 1941 in response to the realisation that the Wehrmacht could not capture Moscow, hence ensuring Nazi Germany's defeat by the Soviet Union. In Mayer's opinion, the Judeocide (Mayer's preferred term