While I wouldn't completely discount cultural and business-environment differences, this is probably the most relevant part,
> Another fatal flaw was that Germany's retail market is already saturated with discounters such as Aldi and Lidl, meaning that any new arrival inevitably finds itself in the midst of a cutthroat price war.
Walmart's model is to do high volume at low margins with a highly optimized supply chain. But that is already exactly the model of Lidl and Aldi, and there's not a lot of room to beat them at that game.
> Another fatal flaw was that Germany's retail market is already saturated with discounters such as Aldi and Lidl, meaning that any new arrival inevitably finds itself in the midst of a cutthroat price war.
Walmart's model is to do high volume at low margins with a highly optimized supply chain. But that is already exactly the model of Lidl and Aldi, and there's not a lot of room to beat them at that game.