In modern day Europe, Germany has officially renounced any claim to these French provinces, although waves of German tourists regularily roll through the feeble French defenses every summer.
Today, French has pretty much surpassed German and the German dialects as the main language. Although culturally still maintaining it's differences, the region is firmly integrated into France, and there is no going back. (For further info, see www.elsass-lothringen.de for German speakers)
Having said that, this region was once hotly contested between the two countries, and when the Germans held the territory, the soccer clubs were integrated in the German leagues.
Lothringen (Lorraine) is mostly French speaking today, and doesn't have as much a German soccer tradition. The main club FC Metz is a regular in the French Championnat. Under the name FV Metz, they played in the Gauliga Westmark 1941-44.
Which brings us to Elsaß, better known as Alsace. Most folks are bilingual. The main stop is of course STRAßBURG, better known by it's French name Strasbourg. (Some day the Germans will stop printing maps that show everything in German.) The local soccer club is the famed Racing Strasbourg, which is a perennial player in the French "Le Championnat". (I believe that it was known as "Rasen SC" in German days, see below.)
The province was forcibly integrated into the Reich in 1940 when the Panzers rolled over France. The region received it's own Gauliga, which was then the highest level in German soccer. Among the local clubs was Sportverein Strassburg 1890, which played in the 10,000 capacity Tivoli Stadium. The club colours were white jersey with a red horizontal stripe and blue shorts. Their success in the local Gauliga was mediocre. A stronger club was Rasen SC Strassburg, which played in the Meinau Stadium (capacity 25,000). Finally, the notorious SS SG Strassburg was the club of the local SS. It was an outgrowth of the older FC Frankonia. All SS-men were ordered to leave their clubs and join the SS sponsored Sportgemeinschaft. Obviously, they ended up as the strongest team, and in 1941/42 had a decent run in the German championship, knocking out a couple of teams before getting blasted by the mighty Schalke. Not surprisng, their team colors were black and white. They played at the Am Wasserturm, with a capacity of around 4,000 (most of whom were probably concentration camp prisoners.) All of the Strassburg based German clubs were disbanded in 1945, although probably some of the SS ended up in the French Foreign Legion Football-Club.
About 100km south of Straßburg is the town of MÜHLHAUSEN (Mulhouse). There was an obscure local German club, ASV Mülhausen, which was disbanded in 1945. More interesting is FC Mülhausen, which was founded in 1893 when Alsace belonged to Germany. In 1918, Alsace became French, so the name change to FC Mulhouse. In 1940, back to FC Mülhausen. 1945, back to FC Mulhouse. This club remains active today.