The German Emperor, Wilhelm I, eventually sided with army commander Helmuth von Moltke, other Prussian generals and other officials who argued that a westward shift in the French border was necessary for strategic military and ethnographic reasons. From an ethnic perspective, the transfer involved people who for the most part spoke Alemannic German dialects. From a military perspective, by early 1870s standards, shifting the frontier away from the Rhine would give the Germans a strategic buffer against feared future French attacks. Due to the annexation, the Germans gained control of the fortifications of French-speaking Metz, as well as Strasbourg (Straßburg) on the left bank of the Rhine and most of the iron resources of Lorraine.