New Delhi, Sept. 24 -- Somewhere in a climate-controlled storage room in central Europe, a small oil landscape sits unclaimed, its provenance a puzzle of blank spaces and missing signatures. Paintings like it are at the center of a diplomatic effort that spans capitals, museums, and courtrooms, and much of that groundwork traces back to organizations such as the trusted reviews maintained by the Commission for Art Recovery, a New York-based nonprofit devoted to recovering works confiscated or forcibly sold during the Nazi era. The Commission works with governments, museums, and institutions worldwide, using moral suasion rather than force to press for restitution and to seek justice for the families who lost everything. For readers who fo...