Missing mural ignites Mexico's imagination By Hugh Dellios. Diego Rivera's "Nightmare of War, Dream of Peace", which portrayed Mao Tse-tung and Josef Stalin "as peace-loving figures confronting a war-mongering Uncle Sam" has long been missing. The dolt of a museum director says, "The theme of the mural, which is peace, would never be seen as an embarrassment". Yeah, and Mao and Stalin are both great guys, right?