singh was indian foreign secretary from 1989 to 1990. prior to becoming governor of arunachal pradesh, he was secretary-general of a think tank in delhi, the university of pennsylvania institute for the advanced study of india. he was appointed as governor of rajasthan on 19 august 2007, left his position as governor of arunachal pradesh on 4 september 2007, and was sworn in as governor of rajasthan on 6 september.