He served in the United States Navy during World War II, achieving the rank of Lieutenant.
Weiss then spent five years working in the Office of Management and Budget and the United States Agency for International Development.
In 1973, President of the United States Richard Nixon nominated Weiss as Director of the Bureau of Politico-Military Affairs; he held this office from August 6, 1973 until January 17, 1974.
In retirement, Weiss continued to act as an adviser on foreign policy and defense affairs.
Weiss died of liver cancer at his home in Bethesda, Maryland, on September 23, 1992, at the age of 67.