 Not able to deal with bureaucracy and boredom, he resigned the military in 1920 and took employment procuring patents and inventions for a British shipbuilding company.He later returned to South Africa, before emigrating to the United States in 1923 where he worked as a teacher.After obtaining U.S. citizenship in 1933, Landau worked as an investigator for the Federal Works Agency and the U.S. Maritime Commission.