Iron ore production in Europe 1900-1945, by country

From the years between 1900 and 1945, France was the largest iron ore producer in Europe; however, output varied greatly per year during the most tumultuous period in Europe's modern history. Iron was one of the most important resources during this time due to its use in the production of steel; the most important metal in war manufacturing. Throughout this time, Germany or France generally had the largest annual iron ore output, and much of this was through control of Alsace-Lorraine.

Alsace-Lorraine

The Franco-Prussian War of 1870 led to the foundation of Germany as a nation state and the German annexation of Alsace and Moselle (northern Lorraine) from France. This was the resource-rich, industrial region just west of the Rhine, and it had a large population with mixed French and German heritage. The emerging German Empire then invested heavily in the region, and it was essential in their empirical expansion and industrialization at the turn of the century, even more so with the outbreak of the First World War. The region was then retroceded to France through the Treaty of Versailles, and in the late 1920s the annual iron output of France was already greater than the other five nations combined. In 1930, the Great Depression then saw the international demand for iron ore drop, but most countries' industries began growing again in 1933 (although the Russian economy was fairly unaffected by the Depression). Alsace Lorraine was then invaded again by Germany in 1940, although iron output was much lower as a large portion of the population was evacuated or conscripted into the German army.

WWII in Scandinavia

In the years leading up to the Second World War, industry in Germany relied heavily on the import of Swedish iron ore, and the German war effort depended on this supply from 1939 onward. While the Scandinavian countries maintained neutrality at the war's outset, Finland's Winter War with the Soviet Union posed a threat to the Swedish iron industry, largely located in the north. Germany then invaded both Denmark and Norway in order to protect its supply chain from an Allied attack from the west, although Sweden was allowed to maintain its neutrality. The German invasion of Scandinavia provided many tactical advantages, and formed a large part of Germany's "Atlantic Wall" defenses, however most historians concur that the primary reason for Germany's invasion of Scandinavia was to protect its trade with Sweden.