<P> From the start of the war, a British blockade on shipments to Germany affected the Reich economy . The Germans were particularly dependent on foreign supplies of oil, coal, and grain . To safeguard Swedish iron ore shipments to Germany, Hitler ordered an attack on Norway, which took place on 9 April 1940 . Much of the country was occupied by German troops by the end of April . Also on 9 April, the Germans invaded and occupied Denmark . </P> <P> Against the judgement of many of his senior military officers, Hitler ordered an attack on France and the Low Countries, which began in May 1940 . They quickly conquered Luxembourg, the Netherlands and Belgium and France surrendered on 22 June . The unexpectedly swift defeat of France resulted in an upswing in Hitler's popularity and an upsurge in war fever . </P> <P> In spite of the provisions of the Hague Convention, industrial firms in the Netherlands, France and Belgium were put to work producing war materiel for the occupying German military . Officials viewed this option as being preferable to their citizens being deported to the Reich as forced labour . </P> <P> The Nazis seized from the French thousands of locomotives and rolling stock, stockpiles of weapons, and raw materials such as copper, tin, oil, and nickel . Payments for occupation costs were demanded and received from France, Belgium, and Norway . Barriers to trade led to hoarding, black markets, and uncertainty about the future . Food supplies were precarious; production dropped in most of Europe, but not as much as during World War I. Greece experienced famine in the first year of occupation and the Netherlands in the last year of the war . </P>

Who had a greater population during the civil war