Joseph WechsbergODESSA is an American codename (from the German: Organisation der ehemaligen SS-Angehörigen, meaning: Organization of Former SS Members) coined in 1946 to cover Nazi underground escape-plans made at the end of World War II by a group of SS officers with the aim of facilitating secret escape routes, and any directly ensuing arrangements. The concept of the existence of an actual ODESSA organisation has circulated widely in fictional spy novels and movies, including Frederick Forsyth's best-selling 1972 thriller The Odessa File. The escape-routes have become known as ratlines. Known goals of elements within the SS included allowing SS members to escape to Argentina or to the Middle East under false passports.
Although an unknown number of wanted Nazis and war criminals escaped Germany and often Europe, most experts deny that an organisation called ODESSA ever existed.