Sally Marks, an American historian, also thought that Germany could pay the reparations. She said the Germans paid the reparations in full and on time as long as the French occupied Düsseldorf in 1921, but stopped after the French were no longer stationed there in 1922. Later that year, the problem became more serious as French and Belgian representatives urged an occupation of the Ruhr Area to force Germany to pay, while the British wanted to lower the reparations. Occupation of the Ruhr began in January 1923. The Allies was quite sure that the German government intended to refuse paying to test if the Allies willed to enforce reparations.