Thyssen was a German nationalist who supported Nazism, believing that limited government control of production and ownership of banking and transportation was a means of preventing the spread of full-fledged communism. In 1923, when French and Belgian troops occupied the Ruhr to punish Germany for not meeting its reparations payments in full, he took part in the nationalist resistance against the occupiers, leading the Ruhr steelmakers in refusing to co-operate in producing coal and steel for them. He was arrested, imprisoned and received a large fine for his activities, which made him a national hero. Through the 1920s, the Thyssen companies continued to expand. Thyssen took over the Thyssen companies on his father's death in 1926, and that same year he formed United Steelworks (Vereinigte Stahlwerke AG), controlling more than 75 percent of Germany's iron ore reserves and employing 200,000 people. He played a prominent role in German commercial life, as head of the German Iron and Steel Industry Association and the Reich Association of German Industry, and as a board member of the Reichsbank.