Through the spring of 1918 of World War I (1914-1918), Germany had been on the offensive on the Western Front but had failed to break the Allies at any point. In July they had been forced back from the river Marne and were once again on the defensive. The Allies were now ready to increase the pressure. The Amiens area was selected and preparations were made in great secrecy with diversionary activity at other points on the line. 32 divisions were involved (twelve French, eight British, five Australian, four Canadian and one American) supported by over 500 tanks and overwhelming airpower.