Occupation of the Ruhr important harbour in Duisburg-Ruhrort, ending French occupation of the Ruhr region on 25 August 1925. According to Sally Marks, the occupation of the Ruhr "was profitable and caused neither the German hyperinflation, which began in 1922 and ballooned because of German responses to the Ruhr occupation, nor the franc's 1924 collapse, which arose from French financial practices and the evaporation of reparations". Marks suggests the profits, after Ruhr-Rhineland occupation costs, were nearly 900 million gold marks. Despite his disagreements with Britain, Poincaré desired to preserve the Anglo-French entente and thus moderated his aims to a degree. His major goal was
Battle of the Ruhr or the "valley of no Return". During the battle other German targets received large attacks. In his study of the German war economy, Adam Tooze stated that during the Battle of the Ruhr, Bomber Command severely disrupted German production. Steel production fell by 200,000 tons. The armaments industry was facing a steel shortfall of 400,000 tons. After doubling production in 1942, production of steel increased only by 20 percent in 1943. Hitler and Speer were forced to cut planned increases in production. This disruption resulted in the "Zulieferungskrise" (sub-components crisis). The increase of aircraft production for the "Luftwaffe" also came