This makes me wonder about art work which Imperial Britain stole from Nigeria (to pick one random colony) during the colonial era. Case in point: the Benin Massacre of 1897, during which British soldiers sacked the kingdom of Benin, killing, pillaging, and making away with untold art work. Much of the art which the imperialists stole from their colonies reside in European museums and private collections today. Some are even being acquired by U.S. organizations such as Boston's Museum Of Fine Arts. This demand for that museum to return the stash of Benin art is tepid at best. And so is this one, which, to its credit, takes care to assign ownership of the stolen Benin art to the Benin royal family.
So, question: is there really a difference between the Nazi looting of Jewish art and Colonial Britain's looting of Benin art? If moral, ethical, or legal arguments can be made for returning the former, why aren't those arguments extensible to the latter?