[citation needed] He was an Under Officer with the National Cadet Corps, and joined the 20th regular course of the Indian Military Academy.
[citation needed] During 1977-1979, Nambiar was a part of the Indian Army Training team in Iraq.
During 1983-1987, he worked as a Military Adviser at the High Commission of India, London.
He served on the United Nations High Level Panel on "Threats, Challenges and Change", which provided basis for the UN Secretary General's report to the 2005 World Summit.
Since 2011, he is a distinguished fellow of the Institute for Defence Studies and Analyses, New Delhi.